10 hidden home renovation costs to watch out for


Possibly the hardest part of beginning any house renovation is that fear of unknown costs, like unearthing costly, problematic, unfix-able things or paying for surveys you didn’t know you needed to, throwing your budgets off completely.

In this post we want to help take the fear of the unknown away a little, so that if you’ve just got an offer accepted on a fixer upper, you can tick off and feel confident that you’ve set aside enough budget if any unknowns arrive.

From surveys to insurance policies, unexpected house renovation costs can add up and no one wants that when your precious pounds would be far better spent on fantastic furnishings to make your new house a home so have a read of this list and talk to other house renovators and tradesmen for their advice.

Remember if you’re unsure of where to start with your renovation then we have a free Survivor’s Guide to Renovating that can help out. When you read the advice you’ll see that we’re sticklers when it comes to budgeting and planning for a house renovation, and that’s because, well, we’ve learned from our mistakes!

So here goes! A heads up for what to look out for…

1. Insurance


Did you know that not all home renovations are covered by standard home insurance?

As a first port of call, speak to your home insurance provider and see whether they can cover your project. If not you might need to purchase specialist home renovation insurance.

Contractors should legally have their own insurance policies (public liability and employers liability) to cover themselves and their work should any mistakes happen. If you’ve decided to go with an architect, they should cover themselves too. However, there are gaps between these policies that don’t cover all eventualities. Plus, if you’re planning a kitchen extension or loft conversion, your home insurance policy needs to be updated to cover you for this when the work is complete.

Invest in a policy to cover building and contents upon completion of your sale, and alert/update existing policies to cover you for the new work you’ve done. That way, should something bad happen, you’ll only have an excess to pay out for, not a gigantic bill. 

Cost to budget for: Insurance costs vary and you can quickly calculate policies online. Our insurance is roughly £220 per year plus we paid an extra £170 to cover our home during a 3 month kitchen diner renovation.

2. Surveys


The secret to feeling confident about budgeting for a renovation is understanding the building. When it comes to a survey, although they aren’t always a necessary part of home buying, they’re definitely advised if you want to avoid any nasty surprises later on. Having an expert thoroughly survey your property can really inform your budgeting plans. All problems flagged in ours we were able to get estimates for and factor them into our budgeting and renegotiation tactics, so highly advise you get one if you’re taking on a fixer upper.

A Building Survey by a chartered surveyor for example, will look at the bricks and mortar, identifying any issues such as unstable walls or subsidence. They’ll also take a good look at the roof, chimney and anything else that has the potential to hold a problem.

If you’re not confident about which surveys you need, you should check out our guide on the different house survey types.

Cost to budget for: The cost for surveys are from around £400 up to well over £1000. You are free to choose between the various different survey types, the choice is yours but best made in reflection of your type of home, age and history. 

3. Drainage survey

Having the drains inspected in a property can also save big bucks in the long run. When we first moved in to our 1930s semi, our full structural survey flagged that there could be some potential issues with the drains. We instantly paid for a drainage survey given the previous owner lived in the house since 1932 when it was built.

Somehow, we doubt she thought to get someone to have a poke around the drains! ;)

A drainage survey uses CCTV to take a look at any potential structural issues, tree root ingress or blockages which could make for a big bill if it all goes wrong.

Cost to budget for: Drainage surveys cost an average of around £50 to £200 and can be easily be carried out by popping a little camera down there to have a nose around, no groundwork necessary. Our drainage survey cost £210 and spotted a blockage which needed urgently addressing or it could have caused issues to our foundations – we’re so glad we did it.

4. Electrical survey

Did you know that the average cost of rewiring a two bedroom house is around £3,000? Very little can be known about the state of a property’s electrics without an electrical survey. They typically cost from around £150 up to £300 for a 1 bedroom up to 5 bedroom house respectively and during the survey they will inspect the state of switches, sockets, wiring and any other power sources in the house. Of course, if you’re lucky enough to have tradesperson pal to take a look over it for you, that’s a fantastic bonus. But remember, a survey will cover you for anything that’s missed but with a favour from a friend, you only have their word to fall back on. 

Cost to budget for: £150-£300 for the survey itself, then up to £3000 and above for work that may need to be carried out. Our exact costs are in our house renovation costs spreadsheet uk.

5. Planning permission

Planning permission can be puzzling when it comes to what, how and how much. We wrote a full guide to help new renovators understand what’s required, so take a look at our Ultimate Guide to Planning Permission. There’s more than just one flat fee when it comes to getting going through the planning permission process. The cost can depend on which type you’re applying for, the complexity of your project and other local authority fees. Be sure to check out out guide to make sure you know how much it will cost you. 

Cost to budget for: Have a read of the guide.

6. Unforeseen issues or subsidence

Say you opt for just a basic structural survey, or to go without altogether (please don’t do this). What happens when something fishy pops up? Even the most comprehensive of surveys can miss out faults which could cost thousands to rectify.



Really, there’s no way of knowing whether this will happen to you, nor how much you ought to put aside for it but the general consensus is to budget a contingency of +10%-20% on top of what you’ve estimated for your entire renovation project.

If you do this, like we did, you’ll be a confident renovator and in control of your project. Watch our “How to budget for a house renovation” tutorial video and see how you can effectively keep costs under control while adding contingency.


7. Changes in a renovation plan

This happens all the time. You’ve changed your mind on designs or your contractor has decided that what you wanted just isn’t possible so you need to try an alternative approach to something. Very few renovations run strictly to plan so it’s almost inevitable that something may have to change. Depending on the size of what you’re working on, changing plans can come at a sizeable extra cost on top of your renovation budget. The knock on effect also adds time and hassle to your work, with delays running through each contractor if they’re all doing their bit at the same time.

A key example of this happening to us was our chimney breast. We were adamant we wanted to break through and sit the cooker inside the chimney, like we eventually did do. BUT, it cost an extra 2 days in labour fees because the chimney breast was more narrow than we thought, and blocked full of rubble.

Cost to budget for: Hard to tell. If you make sure you add a 10-20% contingency on your overall project this should cover you for unknowns like this.

8. Solicitors costs

This one really is unavoidable unless you’re a dab hand with legal business and wanna DIY it ;) Amongst stamp duty and land tax, solicitors costs tend to get forgotten. A nice slice of your budget could be lost to something that really is a necessity so, depending on your individual case, try to set aside around £850-£1500 for solicitors costs and another £200-£300 on top of that for searches that they’ll take care of. 

Cost to budget for: A quick call to your solicitor will clarify this but average costs are listed above. Our advice is keep track and question everything they charge you for that may not look quite right. It’s your money after all. Don’t be afraid to be up front and ask!

9. Moving costs

Whether you’re moving from a flat, a house or from a room on its own, we often don’t quite appreciate just how much ‘stuff’ we have accumulated. It’s all too easy to pass off your home contents as ‘just a few car runs’ or ‘only one truck load’, when in reality, even with the most nifty packing skills, you should expect multiple trips at the very least. A reputable moving company should be able to give you a rough estimate of rate over the phone (if you’re honest about exactly what needs moving) room by room. Also take into account the price of sturdy packing boxes and plentiful good quality packing tape. Underestimating your moving costs can leave you not only painfully out of pocket but also in a sticky situation if you’ve only arranged for a certain number of hours. 

Cost to budget for: Again, totally depends on how much you own! Have a gigantic clear out before you call around for quotes.

Thanks for reading,

Fi & Neil

Want more help?

You need to check out our free Survivor’s Guide to Renovating which will help you with key areas to avoid, and how to make the most of your renovation.