Can I build a house in my garden?

Can you build a house in your garden?

Yes, many people can, but only with planning permission, and only where the garden passes a set of practical tests. A new self-contained home is never permitted development in England or Wales, so the council decides every case on its merits.

The good news is that most of those tests can be checked from your kitchen table before you spend anything. The checklist below covers them in the order that usually rules gardens in or out: size, access, character, neighbours, title, services and planning policy. If your garden passes the first two, it is worth looking at the rest properly.

Is your garden big enough?

Your garden is big enough when it can hold a new home, its own garden, parking and bins, while leaving the existing house a decent garden and keeping a comfortable distance between the two. There is no national minimum plot size, so each council judges this against its own guidance and the pattern of the street.

Separation distances do most of the work. Many councils use around 21 metres between facing back windows, and around 12 to 15 metres between a back window and a blank side wall, although your council’s own guide decides.

For example, picture a new bungalow facing the back of your house. If your council works to about 21 metres between the two rear walls, you then need the depth of the bungalow itself, its own back garden and a margin to the rear boundary. Add those up and you can see why short gardens rarely work, while long gardens, or wide plots where the new home can sit side-on, often can.

In England, national policy now adds a further test for garden land: the new development should not take up more than twice the footprint of the existing buildings on the site, and at least half of the undeveloped garden should remain, unless the extra building can fit without harming the area’s character.

Can a car, a fire engine and a bin lorry get to it?

A garden plot needs an access that is wide enough, safe where it meets the road, and practical for emergency services and bin collections. Access is the most common deal-breaker, so measure the narrowest point between your house and the boundary early.

In England, Approved Document B normally expects a fire engine to get within 45 metres of all points inside a house, using a route about 3.7 metres wide between kerbs, narrowing to 3.1 metres at a gateway. Where that is not possible, other measures, often sprinklers, may be accepted if building control and the fire service agree. In Wales, every new house must have an automatic fire suppression system anyway, which helps on narrow drives.

Bins matter too. Under Approved Document H, residents should not have to carry waste more than 30 metres to the store, and the collection vehicle should be able to get within about 25 metres of it. The council’s highways team will also look at visibility where the drive meets the road, and at how passing cars would affect the house you are driving past.

Does a new home fit the character of the area?

A new home fits when it follows a pattern the street already has, or sits so quietly that it does not disrupt one. Councils look at plot sizes, building lines, heights, spacing and materials in the surrounding area, and at whether a home behind the street looks natural or out of place.

Look along your street and the one behind. Are there already homes built in back gardens, a rear lane, or a former garage court? Gardens backing onto a road or a lane are often easier than gardens surrounded by other gardens. In England, national policy treats a home that cannot be seen from the street frontage more favourably, while in Wales Planning Policy Wales asks for the special characteristics of an area to be central to the design.

Will it affect the neighbours too much?

It will be acceptable when neighbours keep reasonable privacy, daylight, sunlight and outlook, and are not unduly disturbed by the access. These amenity tests are where many otherwise sensible schemes fail.

Design solves a lot of it. A bungalow or a storey-and-a-half home with rooms in the roof keeps height down. Windows can face along the plot rather than into neighbouring gardens, and upstairs windows can use rooflights or obscure glazing. A drive can be set away from the next-door house with planting and a solid fence.

It is worth talking to the neighbours early. They cannot veto an application, but they will be consulted, and planning-based objections carry weight. Occasionally a neighbour turns out to have the same idea, and two gardens with one shared access make a better scheme than either alone.

Does your title allow it?

Your title allows it if nothing on the register stops building on that land and you can give the new home a legal right of access. Order your title register and title plan from HM Land Registry and read them before anything else.

• Restrictive covenants can stop or limit building; options include indemnity insurance, agreement with the person who benefits, or an application to the Upper Tribunal (Lands Chamber).
• A ransom strip, a strip of land you do not own between your plot and the road, can let its owner demand payment for access.
• If the house is mortgaged, your lender must agree to release the plot from its charge before it is sold.
• Rights of way, shared drives and boundary positions all need checking against the title plan.

Can it be connected to services?

It can if water, drainage, electricity and telecoms can reach it at a sensible cost. Long service runs down a garden add expense, and drainage often decides the layout.

Check for public sewers near or under the plot, because building over or near one may need a build-over agreement with the water company. Surface water needs a plan as well. In England the council will expect to see how rainwater is dealt with, while in Wales building work with a construction area of 100 square metres or more, which includes most single new homes once the drive is counted, needs approval from the council’s SuDS Approval Body before building starts.

What else does planning look at?

Beyond size, access and neighbours, the council will look at trees, wildlife, flood risk, parking and any heritage designations. Each of these can add cost or time, and occasionally rule a plot out.

Trees with a Tree Preservation Order, or in a conservation area, need consent or notice before work. In England, biodiversity net gain rules can apply, although there are exemptions for small sites and they changed again in August 2026, so check the current rules. Wales asks developments to deliver a net benefit for biodiversity. The Community Infrastructure Levy may be charged where your council has adopted it, and the self-build exemption only helps if you claim it before work starts.

Should you build an annexe or a separate home?

Build an annexe if the space will be used as part of your existing household, and a separate home if it needs to stand on its own, be sold, or be let. The difference is about use, not just size, and it changes almost everything.

An annexe shares the main house’s address, garden and usually its access and services. Councils often attach conditions keeping it tied to the main house, so it cannot later be sold or let separately. The Planning Portal’s outbuilding guidance does not cover use as separate, self-contained living accommodation, so do not assume a garden building can become a home without permission.

A separate home needs its own planning permission, its own services, its own address, and usually its own title. It is assessed against the same tests as any new dwelling. Some families start out thinking of an annexe and then find a separate home better suits what they actually want, such as independence for grown-up children or the option to sell later.

What are the next steps if your garden looks suitable?

The next steps are to gather the facts, test the idea with a professional, and then decide whether to sell, partner or build. Doing them in this order avoids paying for drawings on a plot that was never going to work.

• Get your title register and plan, and note any covenants, rights of way or mortgage.
• Search the council’s planning records for your street and the streets behind, including refusals.
• Measure the garden depth and the narrowest point of any possible access.
• Check for conservation areas, protected trees and flood zones on the council’s maps.
• Ask for a free garden plot appraisal, with no cost and no obligation, before paying for design work.
• If it looks viable, consider pre-application advice from the council before a full application.