Advice Before Buying an Old House in the UK
- Real Life Architecture
- Feb 15
- 10 min read
Updated: May 8

Over one million homes are sold in the UK every year, but fewer than 200k of those are new build, which leaves 800k older homes for sale each year. If a new build home has problems, you can usually get the builder to rectify them, at least in theory. And I don't imagine many new build homes are sold to people who want to immediately set about altering or extending the property.
But, buying an old house comes with unique challenges. So, if you are considering buying one of those 800k older homes, what should you look out for?
Well, as it happens, about three years ago I began offering online consultations to homeowners across the UK. People watched my videos about the reality of altering, extending, renovating or building homes and they started asking my advice. I provide consultations for different circumstances but THE most popular one is for people needing advice before they buy a home.
There seems to be a gap in the market. Plenty of lawyers, surveyors and mortgage advisors to answer questions on title deeds, subsidence or interest rates but who do you speak to if the property for sale needs its layout changed or an extension added?
How much will it cost, how long will it take, will it get planning approval, does it comply with the building regulations, is it the best use of money or is there a better option the client hasn't considered?
I get all of these questions in my consultations so I wrote this post looking at the common issues I see when people discuss buying older homes with me.
What I need from a client before a consultation
I regularly get messages through the Real Life Architecture website from people asking if I am able to help them. They want to know if the property they have in mind is suitable for a consultation. Some worry they don't have enough information and others write me multi-paragraph descriptions on their wants and needs. But there is a happy medium. In order for me to give you advice on a property, I need the following four things;
The full postal address of the property. I can use this to check it out on Google Street View and the local planning portal.
Some photos or floor plans. An estate agent's online listing is ideal, these usually have the layout and show the condition of the property.
A brief description of what you need done. Whether it's new heating, replacing the windows, converting the attic, taking down internal walls, adding an extension. I need the full Wishlist.
And finally, I need a budget. I know most people won't have any idea how much building work costs but I need a sum of money that you don't want to go beyond.
Perhaps it's the amount of savings you have or the difference between the mortgage and the sale value of the house. Tell me your upper limit and I can tell you whether it matches your Wishlist.
I don't offer consultations for properties outside the UK. That comes down to restrictions put in place by my insurance, and my own experience. I've spent my career in the UK, so I don’t know enough about construction elsewhere to give professional advice to anyone outside the UK.
That said, if there is one thing I would advise everyone to do before buying an older property, it is
Survey the roof first.
The older the property, the bigger the chance its roof needs some remedial work. Now, you might be thinking that with an older property there are any number of things that need work. The electrics, the heating, the windows, they all might need to be replaced but imagine a scenario where you do all that work, spend your entire budget renovating and modernising inside the house and right at the end you discover the roof is leaking. If it's been leaking for a long time, there is a good chance the roof timbers have been saturated and wet rot has damaged the rafters.
Repairing a roof is never easy or cheap. But imagine having redecorated the house only to see water running down the wall. It's not good. It can be difficult to tell from photos but there are usually signs.

Take this row of semi-detached houses for example. They are around 100 years old and some of the roofs are better than others.
There are slates out of place. Over time, these can let in wind-driven rain.
Evidence of patchy repairs. If they cut corners here, what else might not be maintained properly?
Moss on the slates can mean they are starting to delaminate and may need to be replaced.
The occasional ridge tile has been replaced, again a sign that maintenance was patchy.
Some bay windows have lead flashing on the roof, while others have mortar. Some of the lead flashing looks newer than the lead valleys on the roofs.
This leads me to think the bay window roofs have leaked in the past. Are the timbers inside still in good condition? who knows.
Some chimneys have vegetation growing and washed out pointing, which is a sure sign of damp. The chimney on the far right of the photo is not the same design as the others on the street, it looks like it was partially taken down, which could be another red flag.
Some barge boards have seen better days. They aren’t structural items but in combination with the moss on the roof and damp chimney, this tells me the property has not been maintained for many years.
What other problem might be hidden inside that roof?
And that's the main thing to consider. Having the roof inspected from the outside can only tell you so much. If the roof has leaked over a long period of time it can cause damp and rot on the inside, hidden under floors and inside walls.
And the only way to find hidden problems is to...
Carry out an invasive survey
I regularly advise potential buyers to have an invasive survey carried out. This can mean drilling holes in walls or ceilings, lifting floor boards and generally damaging the fabric of the house to find hidden problems. You can't just walk into someone's house and start ripping it apart without their permission. But I have found that if you offer the current owner a modest financial inducement, they are more likely to agree.
The idea is that you get your lawyer to offer a sum to the current owner. Say £500 or £1k to cover the cost of repairing and decorating the areas you want to survey. In the event the survey uncovers something terrible, and you back out of the purchase, the current owners have some money to repair the damage from the invasive survey.
Keep in mind if you are buying a house with a mortgage, the lenders will insist on a survey, but these are often basic, visual inspections. And there is a question over who the surveyor owes their duty of care to. Is it you, or is it the bank?
If you are planning an invasive survey, get an independent surveyor, who you pay directly and who is not reporting to the bank. You can find qualified surveyors on the RICS website, I've put a link in the description. But surveys only go so far. What happens if you are...
Buying an unusual property
Maybe you want a home with character, maybe the original design is a one-off or maybe the property is being sold at a discount because previous owners made questionable decisions. Variety is the spice of life and I love talking to people about unusual properties.
Take this 1970’s split level house for example. The client wanted to know before they bought the property whether they could make the house larger.

They needed an extra room to use as a study or bedroom and they wanted better access to the rear garden. They had a budget of up to £200k for the work.
The neighbour has extended above their front porch and garage. When I got the planning drawings from the local portal, I could see the headroom inside the new space appears very tight, probably less than 2m.

I suspect my client could get planning permission to do the same but they should consider a flat roof to maximise headroom, rather than a shallow pitch tile roof.
I also told them to talk to their neighbours and enquire about the foundations. Building another story on top of an existing structure, especially a garage, relies on the existing foundations being strong enough, and that isn’t always the case. I made a full video about building above a garage but I advised my client to expect higher than average construction costs if the existing foundations need to be underpinned.
Because the house is built on a steep hillside, it has an upside down layout. The kitchen and living spaces are on the upper floor, with the bedrooms below.

This works because the entrance to the house from the street is on the high side of the slope. You walk into the living space and get this lovely view but you cant access the garden directly without going through the bedrooms.

My client wanted to build a balcony or deck at the rear with steps leading down to the garden. This is feasible, but the planners could refuse permission if it overlooks the neighbour's windows.

The design of that balcony and stairs would need to take the neighbours' privacy into account.
All this was affordable within the budget but if the client also wanted to renovate the property, to rewire it or install a modern central heating system, it could impact the 1970’s wood paneling and replacing that comes at a cost.
Some older houses started life with conventional layouts but previous owners made unconventional changes.
This two-story semi-detached house seems normal enough and my client wanted to discuss making it larger. They had a construction budget of £100k to make the changes they needed.

That's a lot of money but it doesn't go very far in today's world. The client wanted to take out the bay window and fill in this area at the rear of the house, to form a large kitchen, living and dining space.

This would incorporate the existing extension into the new space. That would probably be just about affordable, provided the existing building didn't need major changes. However, the previous owners had made some unusual decisions.
This extension has more than 25% glazing. That is, the amount of glass is greater than 25% of the floor area.

Given the entire roof is glazed and these large windows, the space has more than 100% glazing. The extension is open to the house, not separated by a door and it has kitchen units. None of this complies with today's building regulations.
I couldn’t find when the extension was built and I advised my client to have their lawyers ask if the work was granted building regulations approval. My guess is it wasn’t, at least not in its current layout, but it's always worth asking.

If my client went ahead with the purchase, they would need to make changes. They could keep the large amount of glazing, move the kitchen to somewhere else and then create a door between the extension and the house. If they wanted to keep the kitchen here and avoid separating the room from the house, that glazed roof has to go. A new insulated flat roof could be built over the top.
This would be a marginal additional expense if they built an extension back here at the same time. The client understood their budget was tight and wanted to get my feedback before going ahead with the purchase. They had no idea the kitchen was a problem until they contacted me.
The client for this property understood there could be an issue with the building regulations and sought my advice before making an offer on the flat.
The previous owners had converted the second bedroom to a larger, second bathroom. I'm guessing the property, a ground floor flat, was home to someone with limited mobility.

My client needed the bathroom to be converted back to a bedroom, but they were concerned that changes made to the building by the previous owners now make that impossible.
You can see from these existing and proposed drawings I found on the local planning portal, the flat has been extended and the area outside the existing window had been enclosed.

The window used to look onto the rear garden but now it opens into a tiny courtyard. If converting the bathroom back to a bedroom required an escape window, this wouldn’t work.

For a window to be classified as suitable for escape, it has to be a minimum size but it also has to open into an outdoor space that is deeper than the building is tall.
That little courtyard is just too small. So is an escape window required?
The building has been divided into flats and the topmost floor appears to be more than 4.5m above the external ground. This matters because it sets the criteria for fire safety in the entire building.
The English building regulations give a number of options in this circumstance. The easiest one for my client is to make sure the existing corridor is not more than 9m long, measured from the kitchen door to the entrance door of the flat.

The walls all need to be built from fire-resistant materials and all the doors need to be self-closing and fire-resistant.

I can't tell for a fact using these drawings but it appears to work. I advised the client to have the measurements checked by a surveyor. The good news is that a bedroom in this situation does not need to have an escape window.
One other thing I advised my client is that if they changed this larger bathroom into a bedroom, the original small WC would need to be upgraded to a shower room. It is almost certainly too small and the door needs to open outwards to comply with today's building regulations.
I've previously made a full video about the size and location of bathrooms in a home check it out.
Summary
That is a small sample of the kind of issues I deal with in my online consultation service.
There seems to be an infinite variety of older homes out there. And I really enjoy talking to different people right across the UK and helping them understand what is possible.
My name is Níal and if you would like my advice about your project, no matter where it is in the UK you can book a consultation with me and get specific advice about your property. Please read the terms and conditions before you book.
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