5 top tips for a successful extension project

Undertaking home renovations or building an extension to your home is one of those “most stressful life experiences” along with getting married, selling a house, and having kids (though personally I think having kids tops the list x 100!)

Thing is, your building project needn’t be a stressful experience. Of course mistakes can happen, but I am often surprised by the number of horror stories I hear and wonder how things can go so badly wrong. While I’d usually deem a lot of the processes and procedures to be common sense, perhaps I’m underestimating all those years of studying and the numerous completed projects under my belt – they must have taught me something after all!!

So with this in mind, I decided to create a building project toolkit, because really, it’s all in the preparation! In this article, I’ll give you my top tips for going from brief to budget to build without the stress.

1: Be clear on what you want from your extension, not how you want to achieve it.

By writing down a list of your top priorities, you can give your architect free reign with confidence that they will deliver a design with a solution to your problems and not simply a drawing of your own ideas. 


For example, clearly documenting in your written brief that you need a space for the fish tank, a view of the sandpit so you can keep an eye on the kids whilst cooking tea, and two home office spaces (since working at home and living at work are now one and the same) makes it easy to see if design proposals are headed in the right direction even if they look a little different than you first imagined.

2: Make a comprehensive budget.

I’m not suggesting you count every penny, but it’s well worth taking the time to evaluate your finances in order to set yourself up for success. If you have an upper limit, work backwards from that. There are more costs than simply the building work.

Seek quotes for all the services you’ll need, and in particular be sure to get some ballpark quotes for the big ticket items such as kitchens and glazing at an early stage. Having an idea of what these will come to means you’ll be able to make informed decisions about your budget at each stage of the process. You’ll be able to sort the essentials from the nice to haves.

3: Familiarise yourself with the process.

Contrary to popular belief, there’s more to your extension project than getting your planning permission and finding a builder. Do you know what actually happens before the building work begins? While you don’t necessarily need to know the ins and outs of it all yourself, knowing what to expect and what’s coming next will help to maintain momentum.

Without this understanding, it can feel overwhelming because there are so many decisions to make. But remember: you don’t have to make them all at once. Understanding the process means you can focus on the decisions that are relevant for you at any given time. 

4: Talking of decisions, document them in an orderly fashion. 

Whilst your technical drawings should get you through the Building Regs Approval and certainly get your project built, there are a lot of things that often aren’t on the drawings. Finishes, fixtures and fittings, for example, are all things that will influence the cost of the project and therefore need to be factored in from the start. They will also need coordination at an earlier stage of the build than you might think.

Deciding on these things before you start with the build will save you the stress of a rushed decision and  ensures your builder can price properly. They won’t be surprised by your selections at a later stage if it’s all set out clearly. “I’d like these plug sockets, this flooring, this skirting board, these light fittings. I’m choosing this complex shower fitting and I’d like these labour intensive tiny bathroom tiles…” Thank you very much.

5: Have awkward conversations early on.

Once your drawings and specs are complete and you’ve selected your builder, take a moment to step back. Now is the time to have an uncomfortable conversation in order to protect your interests – make sure you know what’s included in your quote. Don’t let the work begin without knowing exactly what you are paying for.

Equally, make sure your builder is aware of any conditions of consents or obligations they need to fulfill. At this point, you might only have met them a couple of times and you’re about to give them the keys to your house along with permission to do a fair bit of damage before it all comes back together. You’re also likely signing a contract for a big chunk of your life savings so it’s really worth an awkward meeting or two to thrash out all the details (maybe throw in some choccie biccies for good measure).

Make sure it feels right. Don’t be the client who called me two weeks into their project to ask for their builders phone number… when the roof had already been stripped off!

And there you have it, five top tips for a stress-free build! It’s all about:

  • Briefing
  • Budget
  • Understanding the process
  • Documenting decisions
  • Communication

Go from Brief to Budget to Build with ease

Are you embarking on your own project and interested in making your own life easier? You can download the full toolkit of resources to make the process as easy as possible.

Click here to find out more: From Brief to Budget to Build: A toolkit for your home extension project.

5 steps to keeping your home renovation costs under control

They say money can’t buy happiness, but it can buy you a lovely home! The real question is:  how much money do you need to create that dream home? 

“How much will my home renovation project cost?” is one of the most common things I’m asked. Sadly, I don’t have a crystal ball, but I can help you to understand the process, the associated costs and how to budget for your project. Understanding all of this will give you the best chance of getting it right without running out of funds. 

Create a budget from the start

This might sound obvious, but it’s a really straightforward way to keep your costs under control during a project. Map out everything that you’ll need to pay for, then check how much you can realistically afford to spend on the renovation. Don’t forget to hold a healthy contingency fund as well – you can always blow it on a fancy sofa, if it’s left at the end (although it rarely is).

There are plenty of costs outside of the building work itself which are often overlooked but really can mount up. These can include consultants’ fees, applications, and surveys, which all come in the months leading up to your building work.

Don’t forget to factor in VAT – this is a killer 20% at present, so it’s important to understand how this will impact your building work. At the time of writing, extension projects are subject to 20% VAT, whilst new builds are VAT free.

Once the building work is finished, you’ll also need to have funds left over for things like kitchens, flooring and furniture. It’s these finishing touches that feel far away at the start, but which you’ll want to include to finish the job. 

Get an accurate quote for your building work

Now that your budget is ready and your design work is underway, you’ll no doubt want to find out what the building work will cost. 

The best and surest way is to complete the design process, technical drawings and tender documents completely before approaching any builders. This means you’ll have a comprehensive set of information for them to price against. If you pick a well-matched set of builders to price the project then the quotes should come in at a fairly similar level. So, now you know the cost

But, what if the quotes come in and they’re a lot higher than you’re expecting? You’ve spent months, maybe years, to get to this point – to not be able to afford your project would be heartbreaking. 

That’s why getting some early stage cost input can be super important to ensure that you avoid this situation. 

Make the effort with early-stage cost input

Early-stage cost input can be a really useful way to start getting a rough idea of what the build cost will be.

The main downside with attempting to price too soon is that you won’t have finalised everything at this stage so there will be assumptions made. However,  if you can encourage a handful of builders to give you some feedback that’s still a useful starting point, just ensure you understand what is excluded.

They will likely be giving you an indication for the shell of the building, not necessarily the glazing, finishes, landscaping etc. And remember, material and labour prices change, treat this as a rough estimate. 

With your ballpark figure in mind, it’s important to understand that your specification choices later on down the line will impact the overall project cost. Do you choose the £10,000 windows or do you prefer the look of the £20,000 windows? You get my drift.

Square meter rates have their place but only as a VERY broad guide. Other alternatives for early-stage cost planning, and for cost control throughout the whole project, include appointing a quantity surveyor. And whilst this isn’t commonplace on smaller projects, it’s certainly something to consider if your project is particularly complex. 

Value Engineering aka Cost Cutting

Sometimes, in spite of your best laid plans and intentions, your quotes will come in above your budget. If this does happen, don’t panic! Working with your architect and builder you can look for opportunities to make savings. 

Begin by reflecting on your priorities. Do you need a finished space ready to move into? In which case could you scale back on the size and complexity. Or would you be happier to complete the shell, undertaking the painting and finish as you go? If the skinny frame glazing is a must have, could you fit a cheaper kitchen? 

Sometimes you can’t have it all, so it’s worth thinking about what’s most important. The earlier you can make these decisions, the better equipped you will be to make that dream a reality, even if things start to go south. 

Understand your payment schedule

The majority of applications, surveys, and consultants fees are due upon submission of applications or as different stages or services are completed. The building work comes with a similar distribution of costs. It’s not uncommon to pay deposits on bespoke items with long lead times – stairs, doors, windows. 

When it comes to paying your builder it usually goes one of two ways: stage payments or regular valuations. 

Stage payments mean that you pay a pre-agreed amount once certain milestones are reached. For example, when the roof work or the plastering is complete. These are agreed up front, so it’s important to make sure that the milestones are things you understand. Agreeing a milestone of “works complete up to DPC” is all very well, unless you don’t know what the DPC is. My advice is to opt for jargon-free milestones.

Alternatively you can manage your payments on a valuations basis. With your architect or quantity surveyor onboard through the build, they can manage this process for you, inspecting the works and agreeing the builder’s valuation and amount due on a monthly or fortnightly basis.

However you move forward, agree what method you will use before you start work. Ensure that the contract sum is known and agreed in advance, as well as how any retention clauses will work. You might typically hold 2.5% or 5% of the builder’s money back for 6 or 12  months, but don’t spend it in the meantime.

For help sourcing a building contract that’s suitable for domestic projects, which will set out these provisions in detail, I recommend the following resources:

https://www.ribabooks.com/homeowner-contracts
https://www.ribabooks.com/RIBA-Domestic-Building-Contract-2018_9781859468692

Ready to start planning your renovation?

There’s a lot to think about before embarking on a building project – sometimes it can be hard to know where to start!

If you’d like some more support in preparing for your build, I’ve developed a toolkit to get you From Brief to Budget to Build, which includes a budget planner, for more information on these resources click here.

10 Common Mistakes Families make when Extending their Homes and How to Avoid them

As I started to write this I thought I’d struggle to come up with ten, but it was frighteningly easy to identify where things can go wrong if you let them…

1. Considering an extension in isolation

I’m a firm believer in the importance of your whole home working together, that the layout and flow through the spaces allows for your family to live without inconvenience. As someone who lives with their fridge in the garage (what were the previous owners thinking!) I can tell you that designing to overcome the functionality issues is always a priority over fancy finishes. Fear not – relocating the fridge is high on my agenda for my own renovation!

2. Stretching your budget too thin

Don’t be over ambitious, if you want to get to the end and still be able to furnish your home then set a budget and work within it. Remember you will have other costs on top of the build – professional fees, applications etc so budget some of your cash for that too.

3. Rushing the design process

It’s really important that you invest the time in getting your brief and proposals right. Communication is important, if you don’t understand something mention it early on. Can’t visualise it? Ask for a 3d sketch. It’s easy for architects to forget that house plans can seem like a foreign language to the lay person. Imagine trying to read a set of instructions in Greek, you’d likely need a translator, and if the translation didn’t make any sense you’d ask for it to be rephrased. Don’t hurry on confused, seek clarity.

4. Trying to outwit the tenders to save money

If you get 3 or 4 quotes that are all within a few thousand quid, then whether you like it or not – that is likely the cost of doing the work. Proceeding with an anomalously low tender in order to make savings is usually a misguided decision. You may well find the difference creeping back into the project via “extras”, especially if you don’t heed point 6.

5. Opting for a contractor who can start right now

With a few exceptions which we’ll come onto, any contractor worth his salt will be booked up. There’s a reason for this, they’re busy because they come recommended and they’re good at what they do. The exception? Perhaps they’ve had a job fall through, but still be wary and as always seek references. Aligning your ideal timescale with a contractor’s availability is not an easy feat but being realistic with your expectation of how soon you’re going to be able to get cracking will help.

6. Opting to manage your own build to save money on professional services

Now, it doesn’t always end in tears if you go it alone but keeping your architect involved throughout the build will undoubtedly save you a lot of time and hassle. Especially when it comes to figuring out monies due, whether adequate progress is being made, if it’s being built correctly, and it will protect your investment in design, see point 7. In my experience the outcomes are nearly always improved and relationships less strained.

7. Being persuaded to make design changes during the build

I cannot say this loud enough – don’t make changes on site without fully considering the implications – you’ve invested time and love in the design process, don’t spoil it now! I once had a builder tell a client that the property wasn’t deserving of the sleek product we had specified. It was something we had researched in detail along with the client to really bring a wow factor, not gold plated (that option was written off, rightly so!) but it was special and not beyond affordable. Subsequently they convinced the client to select something cheaper and no doubt easier to procure or install. Stick to your guns – don’t sit back at the end looking at your clunky version of what could have been.

8. Starting on site before you have all of your approvals in place

Not just your Planning Permission but your Building Regulations approval too. It’s far easier to change things on paper than in real life. Ensure that the details (especially any that relate to regulations) are figured out before you start, otherwise you’ll risk the time delays and cost uplift of rectifying it when it’s eventually picked up by the Building Control Inspector. You might also need a Party Wall Award or a Build Over Agreement, among other things. Starting your build without your paperwork in place is a sure fire way to elevate the heart rate once you realise that your work could be stopped whilst you sort things out.

9. Thinking your home insurance will cover it

It’s important to establish who is insuring what – be that your existing building, contents, the “works” etc. Depending on your chosen Building Contract (don’t proceed without one), you might even need a Joint Names insurance policy. Check, and double check, with your insurers that between you and your builders everything is covered. Insurance is a complex matter so be sure to seek specialist advice. You’d not be the first to think it’ll all be ok – only to find yourself rushing around in a mad panic after a fire/flood has destroyed your building work – to discover no one can make a claim. These things do happen, don’t take the risk.

10. Doing your own decorating

Ok, I was scraping the barrel for a point 10. but there is some truth in this one too. Whilst you don’t need to be Caravaggio to wield a roller, you do need some proficiency if you want it to look any good. I’ve seen many a pristine plastered wall marred by badly applied paint running into blobby drips. In the grand scheme of things decorating isn’t costly, so leave it to someone who is actually good at it!

If you’re just beginning to think about an extension project why not join my facebook group Easy Project Planning for your Family Home Extension where you can find out more.