Actualité - Buying a semi-detached or terraced house in 2027: a good deal or a fal

Buying a semi-detached or terraced house (maison mitoyenne) in 2027 is often a very good deal: it generally costs 10 to 20% less than a comparable detached house, it uses less energy thanks to its shared walls, and it offers the advantages of a house (a garden, and no co-ownership structure in most cases) at a budget close to that of an apartment. In return, you have to accept being closer to your neighbours, check the soundproofing, and know the rules on party walls (mur mitoyen), whose maintenance and works are decided jointly. A house attached on one side only offers a good compromise between budget and privacy. Here is everything you need to know to buy with peace of mind.

In summary

A semi-detached or terraced house costs, on average, less than a detached house of the same size in the same area.
Fewer exposed walls means less heat loss and often a better DPE (energy performance diagnostic).
The dividing wall is presumed to be a party wall: its maintenance and repairs are shared with the neighbour.
Noise is the first thing to check during viewings.
Resale remains smooth, especially for well-located townhouses.

Why the semi-detached or terraced house is so appealing in 2027

In a market where mortgage rates are rising and budgets are tightening, the semi-detached or terraced house ticks many boxes. And it is no coincidence that it is attracting more and more families.

A more affordable budget

In November 2026, the average 20-year rate is around 3.51%, and house prices have fallen slightly over one year (around −1.3%). In this context, a semi-detached or terraced house often makes it possible to become the owner of a house with a garden for the price of a large apartment. On a budget of €250,000, the difference compared with a detached house can reach €30,000 to €50,000 depending on the area.

A real garden, without co-ownership

Unlike an apartment, a semi-detached or terraced house offers private outdoor space and, in most cases, no property manager (syndic) and no co-ownership charges. Some housing developments (lotissements) do, however, provide for a homeowners' association (association syndicale) for shared areas: find out about this.

Often central locations

Townhouses (maisons de ville), longères, Bordeaux échoppes, village houses (maisons de bourg) or 1970s row houses (maisons en bande): shared walls are very common in town centres and in neighbourhoods close to shops and public transport.

The concrete advantages of a semi-detached or terraced house

Beyond the price, the semi-detached or terraced house has real everyday advantages.

Better energy performance

A house attached on one or two sides has fewer surfaces exposed to the outside. The result: less heat loss and often a lower heating bill. With equal insulation, a semi-detached or terraced house frequently achieves a better DPE than a detached house.

Often a more moderate property tax

The taxe foncière (property tax) depends on the cadastral rental value, which takes into account the surface area and comfort features. A semi-detached or terraced house, generally more compact and on a smaller plot, often bears a more reasonable tax.

Shared maintenance

The party wall is maintained jointly, and the costs are shared with the neighbour. This is a significant financial advantage.

A reassuring environment

Having close neighbours is also a form of security, particularly during holidays. Many owners appreciate this sense of community, especially in family neighbourhoods.

The drawbacks not to be underestimated

To make the right choice, let us also look at the weak points, without taboos.

Noise

This is the number one drawback. In older houses with thick stone walls, the nuisance is often minimal. In some houses from the 1960s to 1980s with thinner walls, the sound of voices, television or footsteps can carry through.

Less privacy

Gardens separated by a simple hedge, more overlooking: living close to neighbours requires a little tolerance on both sides.

Works that must be decided together

Touching the party wall, building against it or adding height to a structure requires, in most cases, the neighbour's agreement. This can hold back some extension projects.

Sometimes limited natural light

With façades only at the front and at the back, some terraced houses are darker, particularly in the central rooms. Orientation is therefore a key criterion.

The party wall: what the law says

Party wall ownership (mitoyenneté) is governed by precise rules in the Code civil. Knowing them helps avoid many disputes. The official website Service-Public.fr sets out the rights and obligations relating to the party wall.

A presumption of joint ownership

A wall separating two properties is presumed to be a party wall, unless proven otherwise: title deed, a registered agreement, or exclusive use for thirty years.

Shared maintenance

Both owners share maintenance costs in proportion to their rights. Each remains responsible for any damage they cause.

Repairs decided together

Repairs and reconstruction are carried out by mutual agreement, except in an emergency. Anyone who undertakes works without agreement, outside an emergency, bears the cost alone.

Building against the wall and raising its height

Building against the party wall in principle requires the neighbour's agreement, ideally in writing. Each owner may raise the height of the wall, provided they comply with planning rules and do not harm the neighbour; the raised section then belongs to them and they maintain it alone.

Points to check during the viewing

A well-conducted viewing will spare you unpleasant surprises. Here is your checklist.

Test the sound insulation

Visit at different times, including in the evening or at the weekend. Stay a few minutes in silence in the rooms adjoining the neighbour, and do not hesitate to ask the seller about it.

Inspect the party wall

Cracks, signs of damp, saltpetre: a party wall in poor condition can lead to shared works… or disputes.

Look at the roof and gutters

In terraced houses, the roof is sometimes continuous. A leak at the neighbour's can have consequences at your home. Ask whether any works have been carried out recently on either side.

Check the easements

Right of way, view, water drainage: the title deed and the notary will inform you about any existing easements.

Analyse the DPE

The energy performance diagnostic (DPE) is essential for anticipating your bills and any possible works. From 1 January 2027, the new electricity conversion coefficient (1.7) may improve the rating of some electrically heated houses.

Finding the right attached house

Not all attached houses are equal. Build quality and location make all the difference.

Attached on one side or both?

A house attached on one side only offers more light, a side façade and greater privacy. It is slightly more expensive than a mid-terrace house, but often easier to resell.

Older or newer?

Older houses with thick walls offer good sound insulation, but sometimes require energy renovation. Newer houses comply with more demanding acoustic and thermal standards.

Comparing listings

To get a precise idea of prices in your area, browse the listings of houses for sale on Optimhome and compare detached and attached houses of equal floor area.

Financing and negotiating your purchase

A semi-detached house is financed like any other house. A few levers can nevertheless help you optimise your project.

Making use of available aid

First-time buyer? The PTZ (zero-interest loan), extended until 31 December 2027, can finance the purchase of an older house requiring renovation work in certain zones, or of a new-build house. The Action Logement loan (up to €30,000 at 1%) can complement your financing plan.

Negotiating on the basis of defects

In 2026, nine out of ten sales are negotiated, with an average margin of 4.8%. Sound insulation that could be improved, a party wall that needs repair or an average DPE (energy performance diagnostic) rating are all legitimate arguments.

Planning a renovation budget

Interior insulation of party walls, window replacement, heat pump: the éco-PTZ (zero-interest eco-loan) can finance up to €50,000 of comprehensive renovation work without interest.

Selling a semi-detached house?

If you own a semi-detached house, good news: this type of property is in high demand among first-time buyers and families in 2027.

Highlighting its strengths

Garden, no co-ownership, controlled energy consumption, proximity to shops: these are strong arguments compared with an apartment at the same price.

Reassuring buyers about the neighbours

Prepare information on the upkeep of the party wall, the work carried out and the good relations with the neighbours. Buyers are very sensitive to this.

Setting the right price

A semi-detached house is compared both with detached houses and with apartments in the area. To start from a solid base, get a free online estimate of your house with Optimhome.

Renovating or extending a semi-detached house

Many buyers choose a semi-detached house with the idea of transforming it to their taste. This is entirely possible, provided you anticipate a few constraints specific to this type of property.

Insulating the party walls

Insulating a party wall from the inside is one of the most cost-effective works: you gain both thermal comfort and acoustic comfort at the same time. A lining with sound insulation and an acoustic plasterboard significantly reduces noise from neighbours. Allow for a few centimetres of thickness lost from the living area.

Building an extension

A veranda or an extension at the bottom of the garden is often possible, but it must comply with the local urban planning document (PLU) (distances, height, footprint) and requires a prior declaration of works or a building permit depending on the surface area created. If the extension rests against the party wall, the neighbour's written agreement is strongly recommended.

Converting the attic space

In town houses, converting the attic space is often the best way to gain square metres. Pay attention to the shared roof in terraced houses: a change in roof pitch or the addition of dormer windows must be consistent with the neighbouring houses, and the PLU may regulate it.

Changing the heating system

Installing an air-to-water heat pump involves an outdoor unit, which is a source of noise for the neighbours. Place it on the side opposite the neighbour, on anti-vibration mounts, and check the applicable planning rules.

Getting along with your neighbours day to day

Quality of life in a semi-detached house depends greatly on neighbourly relations. A few good practices are often enough to avoid tensions.

Prevention is better than cure

Before noisy works, a party or the felling of a tree, simply let your neighbours know. This small gesture defuses most conflicts.

Putting agreements in writing

Sharing wall maintenance costs, planting a hedge, roof work: a simple letter signed by both parties avoids misunderstandings years later, and will also reassure a future buyer.

In case of disagreement

If dialogue is not enough, turning to a conciliateur de justice (a court-appointed mediator) is free and often effective. The judge only steps in as a last resort, in particular in cases of abnormal neighbourhood disturbance (trouble anormal de voisinage).

Semi-detached house or apartment: how to decide?

With the same budget, many buyers hesitate between a large apartment and a small semi-detached house. Here are a few pointers to help you choose.

The real monthly cost

An apartment involves condominium charges (charges de copropriété), which can sometimes be high if there is a lift, a caretaker or collective heating. A semi-detached house generally has none, but all the maintenance falls to you: roof, façade, boiler, garden. Run the numbers over ten years to compare with a clear head.

Everyday freedom

In a house, you alone decide on your renovation work, without waiting for a general meeting (assemblée générale) to vote. It is a real comfort if you enjoy fitting out and personalising your home.

Resale

Both types of property resell well when they are well located. A semi-detached house with a garden is particularly appealing to families and young couples, a large clientele in most mid-sized cities.

The practical tip

Visit at least twice, including once in the evening, to assess the noise.
Ask the seller for the invoices for work carried out on the party wall and the roof.
Have the notary specify the status of the wall (shared or private) and any existing easements.
Compare the DPE (energy performance diagnostic) with that of a detached house in the same area.
Favour a house attached on one side only if light and privacy are priorities for you.

The professional's advice

"A semi-detached house also means a neighbour. During the visit, I always advise buyers to take a look at the house next door: well-kept façade, tidy garden, repaired shutters… These are good indicators of life on the street. And if the opportunity arises, don't hesitate to exchange a few words with the neighbours: in two minutes, you will often learn more about the neighbourhood and the noise than in two hours of viewing."

Getting support to find the rare gem

The best semi-detached houses go quickly, especially in town centres and family neighbourhoods.

To be informed first and to view properties in the best conditions, contact an Optimhome real estate advisor near you: they know the streets, the types of construction and the real prices in your area.

Conclusion

Buying a semi-detached house in 2027 is often the most accessible way to own a house with a garden, with a controlled budget and lower energy consumption. Noise, privacy and the rules governing the party wall deserve particular attention, but with good viewings, the right documents and well-conducted negotiation, you can make an excellent deal.

Do you know a neighbour or relative who wants to sell their house? Recommend them and be rewarded by becoming an Optimhome business referrer.

FAQ - Frequently asked questions

Is a semi-detached house cheaper?

Yes, generally 10 to 20% cheaper than a comparable detached house in the same area, depending on location and condition.

Who pays for the maintenance of the party wall?

Both owners share the maintenance costs in proportion to their rights. Each person alone pays for any damage they cause.

Can you carry out work on a party wall?

Repairs are decided by mutual agreement, except in emergencies. Building a structure against the wall in principle requires the neighbour's consent.

Is a semi-detached house noisy?

It depends on the construction: the thick walls of older houses often insulate well, while some houses from the 1960s-1980s are noisier.

Does a semi-detached house resell well?

Yes, it is highly sought after by first-time buyers and families, especially in town centres or close to shops.

How can you tell whether a wall is party wall (mitoyen)?

It is presumed to be a party wall, unless proven otherwise by a title deed, a published agreement or exclusive use for thirty years. The notary can check.

Is the DPE better for a semi-detached or terraced house (maison mitoyenne)?

Often yes, because it has fewer walls exposed to the outside, which reduces heat loss.

Can you insulate a party wall?

Yes, from the inside, without your neighbour's consent since you are working on your own side. It is even an effective solution against noise.

Is your neighbour's consent required for an extension to a house that shares a party wall?

If the extension rests on the party wall, the neighbour's consent is in principle required. In all cases, you must comply with the local urban planning document (plan local d'urbanisme) and submit the appropriate application for authorisation.