TOP 10 THINGS TO BE AWARE OF WHEN BUILDING A HOUSE EXTENSION

6 months into our Renovation and the ground floor and 1st floor extensions are complete.

Building a house extension is an exciting experience. I recently wrote a post on ‘A Guide to building work and all the extra costs that go into it’ which you can read here, but I thought i’d recap some of the key points which I feel are the most important to consider from the offset.

Here’s a checklist of things to be aware of when building a house extension.

How much can you extend a house without planning permission?

Under permitted development rights, you can extend your house to a certain extent without

planning permission, but this varies based on the type of extension. For a single storey

house extension, it can be no more than 4m in height when it is within 2m of a boundary,

with eaves no higher than 3m, and there are further guidelines for the width of the extension

depending on whether it is detached or semi-detached.

As there are so many specific requirements that need to be met depending on the type of

extension, it is best to err on the side of caution and consult an expert before beginning the

construction.

Do I need to comply with building regulations?

Before going ahead with building a house extension, you need to contact your local authority

to be sure that your planned extension complies with building regulations. These set out key

requirements to ensure that a building is safe, including in terms of fire safety and damp

proofing. Learn about how to damp proof walls using paint to maximise your chances of

approval.

Who do I need to hire to build my house extension?

You may choose to do the construction yourself, or in other cases, you might choose an

architect to design the plans for you. You can select contractors to build the extension, or you may let the architect choose their

own contractors. If you want an extra level of control over your construction, you can project

manage the construction yourself, or hire a project manager to oversee the work.

Do some research online, talk to friends about local contractors, and if you wish to take on

the project yourself, consider carefully whether you have enough time to dedicate to the

work.

How will construction work affect my home?

You should also consider the impact contractors will have on your home. As well as the

disruption to your home life that will come with builders entering your home, you will need to

ensure there is enough room for contractors to park their vehicles and store materials.

Will you feel comfortable staying in your home during the construction? You may need to

factor in costs for accommodation or have discussions with family members about possibly

staying with them whilst the work is being done to your property.

Do I need to take out site insurance?

It is vital to ensure that your home insurers are aware of any intended extensions to your

property. Many home insurance policies will not cover extensions, and your existing policy

may be undermined by any structures you build. You should never assume that builders will have insurance. In some cases, even if they do

have insurance, you may be required to prove you are not at fault when taking out a legal

claim against them.

Will my house extension cause conflict with my neighbours?

The Party Wall Act 1996 prevents and resolves disputes over party walls between

neighbouring buildings. If you intend to build a house extension on or close to a boundary

that you share with a neighbour, you will need to give your neighbours notice of your

intentions. If your neighbours disagree with the extension, the act provides a mechanism for

resolving disputes.

Factor in purchases for blinds, curtains and partitions if you feel concerned about lack of

privacy between the properties.

How should I plan for the costs of building a house extension?

You should factor your costs for the extension well in advance, including contingency plans,

as it is common for housing renovations to reveal wider issues with housing structure, etc. Before writing a list of planned costs for materials and construction, ensure you have

factored in all aspects of the work. You may need to reserve extra money for insurance,

plumbing, VAT charges, accommodation, amongst other things.

It’s vital not to cut back on quality, as selecting the highest quality materials secures the safety of your extension. For example, C24 Timber is the best choice for floor joists due to their high strength

How should I factor in the position of white goods?

If you intend for your extension to be a kitchen or bathroom, you will need to consider where

your plumbing or white goods will go, and if you need to have anything installed. Discuss the locations of any white goods, sinks or toilets with your designer and any building

contractors to ensure they are aware of changes that will be required. This factoring of white goods is a thing to consider if it’s a kitchen you’re extending, helping you to prepare for the cost of new appliances, including a fridge/ freezer that fits the new dimensions of your kitchen. 

Will I have to pay VAT when building a house extension?

Labour and materials for building a house extension will generally be subject to VAT at a

rate of 20%. You may be able to avoid the extra VAT charges on labour by using a local

builder who is not VAT registered, but you will still be required to pay VAT for any materials

Used. You may also be able to claim relief from VAT charges if your property is a listed or

unoccupied home, but you will be required to use a VAT registered builder.

How much glazing can I add to my house extension?

Building regulations dictate that the amount of glazing in an extension should be limited to

25% of the extension’s floor area. If your intended extension exceeds this amount, you can

deduct the total amount of windows and doors that have been removed due to the extension,

which should help you to fit within the guidelines.

If the amount of glazing still exceeds 25% at this stage, you will need to show that the

extension’s CO2 rate would be no higher than a compliant structure of the same size.

Now you’ve gone through the building a house extension checklist, it’s time to put your plans

into action. Take these aspects into account, and you’ll have a fantastic new extension that is fully compliant and fits your everyday needs.

A GUIDE TO BUILDING WORK (AND ALL THE EXTRA COSTS THAT GO WITH IT)

Hi, This is me and our ‘Rat House’ Renovation- A detached 1930’s house in Watford

This blog post is sponsored by Hoppy. All views and opinions are 100% my own.

Whether you’ve owned your property for a while, or you’re on the search for the perfect doer upper. I’m sure if you’re anything like me, you’ve had conversations with your partner, friends or family about “doing a little loft extension”, or “let’s just fill in that side return, surely it can’t cost that much”.

I’m currently living through our second build as I type this. This time round, we bought the doer upper - A detached 1930’s house in Watford, Hertfordshire. We’re adding a 7 metre (7m) ground floor extension to the back for an open plan kitchen/ dining room and a 3.5m first floor extension for an extra bedroom and en-suite. In building terms this is on a much grander scale than our last build which was a 2-bedroom, 1-bathroom loft extension on a Victorian terrace.

(If you want to read more about our 1930’s build, I’ve written about it here).

Perhaps for our third build we’ll buy a plot of land and do a self-build to earn the top building badge of honour. Ah, who am I kidding? After this one I think we’ll be done for a while, if not forever.  Although I do think I’ve got the building bug. Just don’t tell my husband. *wink

So, you’ve decided you want to convert your garage into a playroom, you’ve done your Pinterest boards and Sally on Instagram is doing it so it must be affordable and doable right? Think again. One thing no one really talks about is the amount of administration, planning, time and expense which you may incur by having the smallest of renovation work done.

I’m going to take you on a step by step guide to all the extra costs which you need to consider before taking on any building project of any size, because what people don’t tell you is all of this stuff.

So here goes..

Architect

Speak to an expert. The initial talk with an architect will be free, so pick their brain when it comes to what you can and can’t do.

Disclaimer ** Architects don’t know for certain what will or won’t get approved by your local authority, so do check your local planning portal to see what your neighbours have done already. This will give you a good gauge on what is and isn’t possible in your area.

And remember that just because someone down your road has the same extension, it doesn’t mean it will definitely get approved. You need to take into account neighbours objections.

What an architect will do though once you’ve paid your fee is:

·      Carry out measured site survey and take required photographs.

·       Prepare existing floor plan.

·      Prepare existing elevations.

·      Prepare existing section.

·      Prepare existing site plan.

·      Prepare proposed floor plan.

·      Prepare proposed elevations.

·      Prepare proposed site plan and block plan.

·      Prepare proposed section.

·      Submit planning application to local authority via the planning portal. – Not all architects will do this, but some might include this in their price.

The Cost

Once you’re ready to get the drawings done, these could cost as little as £1k, but up to £10k depending on the size and detail of the project.

Our architect drawings for our 1930’s detached house with a new 7m ground floor extension and a 3.5m 1st floor were £1.5k + Vat

 Structural Engineer

Some architects will have their own structural engineer within their company, but some won’t. The structural engineer drawings are vital for any builder to work from, otherwise all you have is a very pretty, slightly complex line drawing from the architect for the builder to work off- which is basically not very helpful. The structural engineer plans will lay out steel sizes, foundation depths, insulation thicknesses and so on to make sure the build complies with the most up to date building control regulations.

Make sure when you get your quote for the architect drawings that its clear whether the structural drawings are or aren’t included in the price, because quite often this is a surprise to pay-out later down the line.

What you get for your money from your structural engineer is:

·      Prepare Structural Drawings.

·      Prepare Building Control Drawings.

·      Prepare Drainage Drawings.

·      Prepare Structural Calculations.

·      Prepare Construction Drawings.

·      Submit initial Notice for Building Control (Fees not included).

·      Submit Water Build Over Contract (if needed- and cost wouldn’t be included) 

The Cost

Our structural engineer drawings were included with our architect, but I’ve broken this amount down from the rest, which was roughly another £1,200+Vat

Planning Application

You have your architect drawings and you’re ready to make that planning application. You don’t actually need structural calculations to apply for the building notice – all you need is the architect drawings, so it’s probably best that you wait to see if your plans are approved before paying for the structural calculations as you might need to make changes, or worst case scenario, they won’t be approved and you would have wasted your money.

Some Architects will build this cost in and make the submission for you.

You can apply for planning before owning the property but the current owner or part owners of the property or Leaseholders with at least 7 years lease remaining or any agricultural tenants will need to be informed.

Firstly, the property owners may be more reluctant to sell the property to you. Visits from architects and additional delays caused may lead them to prefer a different buyer, and once you receive planning permission, the seller may choose to put the property back on the market at a higher price. They can now add the fact that planning permission has been approved for the works you have proposed.

Alternatively, you can wait 21 days from completing on the property and you won’t need anyones prior permission to apply.

It’s also worth noting that with most councils you have 3 years to start your building work from when your application is approved. This is three years to get a fork in the ground and get the building control officer out. The work doesn’t need to be finished in this time, but does have to start, otherwise you need to start the application process all over again. It’s worth noting that if your application has multiple works, the permission doesn’t have a timer and you can come back to do other bits any time as long as something has started.

The cost

If you need to apply yourself, the cost varies from £206 - £462 depending on the work, and this price might vary if the property is in a conservation area.

You or your architect will also need to pay £72 for Ordnance Survey
Extract (which is a satellite map which you can purchase online). This must be submitted with any application.

Party Wall acts

If your planning is successful, your local authority might ask you to obtain a party wall act with each of your neighbours. This all depends on how close the neighbouring properties are.

** Even detached houses have to comply with the party wall act, unless your property is within 6 meters of any neighbour’s boundary.

I’ve written a blog post about Party wall acts, which you can read here.

In summary, these don’t have to cost anything and is just a matter of asking your neighbour to sign a legal document which means you will make a mend if any damage is caused to their property during the build. However, they can also become expensive if the neighbour refuses to sign.

But one thing to remember is your neighbour cannot stop your building work happening, even if they refuse to sign. It just means you will have to pay for a party wall award which means having an independent structural engineer draw up a contract.

Also, worth noting that you are meant to give your neighbours 30 days’ notice of work starting.

The cost

They can vary, but if you need to pay a structural engineer to put a party wall award in place it can cost anything from £900 +, and you could have two on your hands if both neighbours don’t comply and want awards in place.

It’s also worth noting that you can’t use a structural engineer which you’ve used before. They must be impartial to both you and your neighbour as they will act as a mediator if any damage is caused.

 Building Control

Things are now progressing, you’ve got your planning permission, your structural drawings are done, and you have your party wall act signed. It’s time for you to start building.

Now you must notify your local authority’s building control with intent to start the building work 48 hours prior to starting.

The cost of this for us was £235

Around six weeks later you will need to pay the further building control fee which covers all site visits and will pay for the certificate at the end by building control when they sign the project off. For us this cost was £630

The start of our 1st floor 3.75m extension

Builders Quotes

Depending on what type of work you’re having, you might be planning to project manage the work yourself i.e. organise your own trades, brick layers, plumbers, electricians etc or perhaps you’ll get someone in to project manage it for you. Whichever you decide to do, make sure you get three separate quotes and ask them break down each cost, and don’t be afraid to challenge. Ask if the cost is fixed and final and isn’t an estimate.

Ask if waste and skips will be included in the price. A large skip can cost £400 and can add up pretty quick when filling with old plaster and timber.

In London and the South East, the average cost per m2 is around £1,500-£2,000+. For two-storey extensions, add 50% to the cost of a single-storey extension. If you want to add a bathroom or kitchen, add £5,000-£10,000 for the plumbing. This doesn’t include the tiles and bathroom suites which you want to install, so make sure you keep some budget back for them too.

Here’s me and my pink hard hat ;)

Dropped Kerbs

This might not apply to your property, but if it does and you want your kerb dropping this ranges from £1k - £3.5k per property (depending on how many drop kerbs you require and if it’s a carriage driveway) for your local authority to carry out this work.

Water - Build over agreement

 A Build Over Agreement is needed when you want to build over a public sewer and need your local authority's consent to do so ‘in the form of a “build over agreement”.

This can cost in the region of £500.

Driveway

A driveway is something to bare in mind early on as you can apply for it at the same time as your house plans, otherwise you’ll need to make an extra application with an additional cost.

Don’t forget to consider drainage  and soakaways.

The cost

A driveway will cost you in the region from £3k + vat upwards.

Our Garden once all the trees had been cleared.

Garden

Your new extension looks lovely, but it’s wrecked your old patio/ garden where the builder used it to store his bricks and cement.

Consider keeping some budget back to re do your patio/ garden.

 The cost:

This is very hard to guesstimate. We have had quotes for as much as £16k to level, re landscape, lay patio and decking and this doesn’t include the slabs or decking materials.

For now, this one’s going to have to wait a while.

I hope this is helpful and hasn’t put you off. I certainly wish I had read something like this before I started our first build. It’s always good to have a plan.

Good luck and remember I’m always available on  my Instagram @Houselust for a bit of building advice if you ever need to ask me anything else.

Just me having one of those ‘what the hell have we done’ moments whilst looking at our mouldy windows :)

OUR RENOVATION JOURNEY: PARTY WALL ACTS AND WHY WE NEED THEM

The back of our New House. We needed a party wall act with both our neighbours (Even the one on the left).

If you’re thinking of submitting plans for an extension or have already submitted them, but have heard the term ‘Party Wall’ and don’t know if it applies to you, then this post is for YOU!

I found this area all quite mind boggling because I didn’t think Party Wall’s applied to detached houses, but it still does. And what you don’t want to do, is leave it to the last minute like I did.

So, today’s post is all about… you guessed it… Party Walls.

Why you need one, what they’re for and why they can be a massive headache if you don’t get it sorted before your building work starts, not to mention the extra cost which you might not have accounted for if you have to involve a party wall surveyor.

So, what is a party wall Act?

Sadly, it’s not a party of any kind. Boooo! And it doesn’t even have to involve a ‘Wall’ to be needed.

The Party Wall Act came into force on 1 July 1997 and applies throughout England and Wales. (The Act does not apply to Scotland or Northern Ireland)

 The Act provides a framework for preventing or resolving disputes in relation to party walls, party structures, boundary walls and excavations near neighbouring buildings.

Basically, in a nutshell, it serves as a legal document between you and your neighbour to stop you from falling out when the digging and building work commences (although it can’t actually stop you from falling out). But it’s there to protect your lovely neighbour’s property. This could be from you hammering a massive steal into their walls for an extension, or it could be because you need to excavate near their foundations to dig your own foundations. It’s your way of politely serving notice that you will be whacking a great big steel into their neighbouring wall when building your extension or digging next to their foundations which you’ve now had planning permission for.  You’re politely letting them know in a legal document – aka serving notice.

And it’s there to cover the neighbour so that if you cause any damage, you will make good - aka resolve any disputes.

Who needs a party wall Act?

Anyone intending to carry out work (anywhere in England and Wales) of the kinds described in the Act must give Adjoining Owners notice of their intentions. The Act applies even to Crown, Government and Local Authority owned property.

What does the Act Cover?

• Various work that is going to be carried out directly to an existing party wall or party structure – ie on a Mid terrace house – loft conversions between neighbouring properties, ground floor/ 1st floor extensions on Semi-detached houses.

•    New building at or astride the boundary line between properties.

• Excavation within 3 or 6 metres of a neighbouring building(s) or structure(s), depending on the depth of the hole or proposed foundations. So in a nutshell, if your property is within 3-6 meters of your neighbour’s property and you will be digging for foundation work, you will still need a Party Wall Act even if your walls aren’t adjoining.

The document

You can find generic documents online which will help as a guide when serving notice on your neighbour. Just make sure you amend the details to be yours and your neighbours. And in the foundation section, try and give as much information from your structural engineer as you possibly can. I.e.- will there be any special foundations?

Then attach a consent form for them to sign and return, and make sure you stipulate a date for which the building work will commence. You’re meant to give your neighbours TWO months’ notice – but if your neighbours are nice and understanding you can talk to them about bringing the start date forward.

I’ve linked templates below that you can adapt and use for this purpose. - Because sharing is caring…

DOWNLOAD A FREE PARTY WALL TEMPLATE LETTER

and

DOWNLOAD A FREE PARTY WALL CONSENT FORM

Can they refuse to sign it?

Yes, they can. But just remember that even if they do refuse to sign the free Party Wall Act, it doesn’t mean your building work can’t happen. It will just delay things until you have appointed a Party Wall surveyor and a Party Wall Award has been served to the neighbour.

What is a Party Wall Surveyor and What do they do?

This is where it gets a little complicated. If your neighbour refuses to sign the free document, they are entitled to have their own Party Wall Surveyor – at YOUR COST.

They are actually entitled to their own Party Wall Surveyor, in addition to one that will represent you. I.e. two different Party Wall Surveyors. They can even request a third to act as an adjudicator if they really want to be difficult and these will all be at YOUR COST.

But they can also choose to use one surveyor which will represent the two of you. This is the ideal option and will be the least expensive option to you. This is what YOU want.

The Surveyor will do an assessment of your neighbour’s property which will involve taking numerous photos of their internals, externals and their garden, noting any previous movement, cracks etc. In the long run this will help you if they say there’s been movement and your building work caused it etc.

Then once they have done the assessment, they will work on a schedule to ensure the excavation or structural work is done as safely and with least disruption as possible to the neighbouring property and then the Party Wall Award will be Served. This is where your structural engineer will come into play in a big way as they will be asked by the Party Wall Surveyor to go into more detail regarding foundations or joining walls/ steels etc. I’d also make sure you have this cost covered in your structural engineers initial quote, as you don’t want them asking for more money when you’ve already paid them and now have Surveyors to pay for as this cost can suddenly escalate quite rapidly.

Your structural engineer will produce a series of sketches like this for the Party wall Surveyor to show the relationship with the neighbouring property.

How much will a Party Award cost?

You’re looking at between £700-£1500 (including VAT) per surveyor. It depends on the project size and where in the UK you are located.

Keep in mind that if you need a Party Wall surveyor award with each neighbour this could double or even triple in cost for you.

When Should I serve the Party Wall Act to my neighbours?

Do it as soon as possible. As I mentioned before you’re meant to give your neighbours two months’ notice before starting work, and you will need to have this in place before starting, otherwise you will only be able to do the work which is within 6m or more from their property.

You can even serve the notice to your neighbours at the same time as you submit your planning application. This way you can talk your neighbours through your plans and gauge their reaction to whether or not you think they will be happy to sign the free notice and if not start researching for a surveyor.

It’s a stressful time, but once you get over this part the building work is all GO GO GO.

Good luck with your build if you’re about to start one, or if your knee deep in one already send me the address and I’ll send the wine to help steady the nerves. Just kidding. I need ALL the wine right now for mine.