selling

What adds value to a house? Location, type, loft, conservatory, kitchen and paperwork, ranked

What adds value to a house, ranked: location and property type from August 2026 UK HPI data, then loft, conservatory and kitchen, with no invented percentages.

4 min read
Last reviewed 5 November 2026
By Your Property Check team

Part 1 of 9

How we ranked these

General information, not legal or financial advice. People ask what adds value to a house and expect a percentage for each improvement. We could not find one from an official source that we could read, so we do not publish one. Instead we ranked the factors by what the data shows. The first two use the UK House Price Index (HM Land Registry and ONS) held in our data, month August 2026, file UK-HPI-full-file-2026-08.csv. The rest rely on what GOV.UK and the Planning Portal say. The ordering is our editorial judgement. We read the sources on 5 November 2026.

Part 2 of 9

1. Location

Where the house is has the largest effect we can show. The UK average was £273,037 in August 2026. The London average was £554,430 and the North East average was £165,640, so London was about 3.3 times the North East. No improvement to a single house changes its region. This is why a rule of thumb that works in one area does not carry to another.

Part 3 of 9

2. Property type

The same data splits the average by type. The percentages show each type against the terraced average.

Type	UK average, August 2026	Against terraced
Detached	£443,846	91% higher
Semi-detached	£278,675	20% higher
Terraced	£232,505	baseline
Flat	£194,148	16% lower

The gap changes by region. In the English regions, the detached average was between 80% (London and East of England) and 118% (North West) above the terraced average. London flats were 34% below terraced homes, while in the North West they were 21% below. These are averages of different homes, not what a change to your home would add.

Part 4 of 9

3. Space: loft, extension, extra bedroom

Moving up a type, such as turning a terrace into something larger, is not a realistic project, but adding space is. A bigger home is usually compared with bigger homes nearby. We found no official figure for how much a loft conversion or extension adds. What the sources do say is whether you may be able to build without planning permission.

Loft conversion. The Planning Portal says loft conversions are generally permitted development in England if limits are met, with a volume allowance of 40 cubic metres for terraced houses and 50 otherwise. It does not apply to flats or to land such as conservation areas, and side-facing windows must be obscure-glazed.
Extension. GOV.UK lists an extension as a major change that probably needs planning permission, and says to check with your local planning authority.
Conservatory. The GOV.UK planning page we read does not mention conservatories, so check locally.

Our planning applications tool lets you see what has been approved nearby, which shows what neighbours have been allowed to build.

Part 5 of 9

4. Paperwork and certificates

Work that adds space is only as valuable as its paperwork. GOV.UK says that without building regulations approval you will not have the certificates of compliance you may need when you sell. A buyer's solicitor can ask for them. If the work is not signed off, that can delay a sale or reduce what a buyer is willing to pay. Keep planning decisions and completion certificates together with the title documents.

Part 6 of 9

5. Kitchen, bathroom and decoration

We found no official source that prices these. They work mainly by removing a reason for a buyer to knock the price down. Our view, not a measured figure, is that cosmetic work helps most when the home would otherwise look tired against its sold comparables.

Part 7 of 9

6. Energy efficiency

An Energy Performance Certificate rates a home from A to G, and you can look up a certificate with our EPC finder. We did not find a published price premium per band that we could read, so we do not state one.

Part 8 of 9

Over-improving for the street

The most expensive mistake in this list is spending beyond what the street supports. A home's price is anchored by recent sales of similar homes nearby. Spend more than that gap and you may not get it back. Before you commit, compare what comparable homes with the feature have sold for on your street. Our house value check and the sold prices tool show real Land Registry sales with the working shown. See also our guide to how to find out what your house is worth.

Part 9 of 9

What to do before spending

Get a value range for the home as it is.
Look at sold prices of homes with and without the feature.
Check planning and building regulations, and keep the certificates.

This page is general information, not legal or financial advice.

Our take

Check the street's sold prices before you spend

Our view: people over-spend because they trust a rule of thumb. The data says the biggest differences are where the house is and what type it is, and no official source we read gives a percentage for a kitchen, conservatory or loft. The common mistake is to improve beyond what the street supports.

Use our free house value check to see an honest value range from real HM Land Registry sold prices in your postcode, with the comparable sales shown. Look at what similar homes with the feature sold for before you commit to the work.

Check my value

Our opinion, drawn from the facts on this page: not advice and not a forecast. We earn from OfferCheck reports and from introducing sellers to cash buyers, so weigh it with that in mind (see our disclosure). We are not authorised or regulated by the FCA.

Questions, answered

Frequently asked questions

Does a loft conversion add value?

We found no official figure for the uplift. The Planning Portal says loft conversions are generally permitted development in England if limits are met, up to 40 cubic metres for terraced houses and 50 otherwise. Compare sold prices of similar homes with and without a loft room.

Does a conservatory add value?

We found no official figure. The GOV.UK planning permission page we read does not mention conservatories, so check with your local planning authority. Compare sold prices on your street to judge the effect.

What adds the most value to a house?

Of the factors we can show with data, location and property type. In August 2026 the UK average for a detached home was £443,846 and for a terraced home £232,505, from the UK House Price Index.

Do I need building regulations approval to add value?

For many works, yes. GOV.UK says that without approval you may not have the certificates of compliance you may need when you sell your home, and the person doing the work could be prosecuted and fined.

Can I over-improve my house?

Yes. Prices are anchored by recent sales of similar homes nearby. Spending beyond what comparable sales on your street support may not be recovered, so check sold prices before you commit.

Where this comes from

Sources

Last reviewed 5 November 2026 by the Your Property Check team. This page is general information, not legal, tax or financial advice. For your own situation, speak to a conveyancing solicitor or another qualified professional.