How much does a wrap around extension cost?

What is a Wrap Around Extension?

Wrap around extensions are a type of home extension that builds around two sides of your property. For example, your extension can extend out from the rear of your home, and also around the side in an ‘L’ shape.

This choice of extension is a great option for homes with dead space along the side of the property. They are most popular in period homes, where you may not wish to use up valuable garden space but have an available capacity around the sides of the building.

Why are homeowners opting for wrap around conversions?

This type of conversion maximises your floor space whilst minimising the reduction in the outdoor area. A wrap around conversion makes the most of alleyways and pathways running alongside your home that aren’t large enough to serve any other useful purpose.

Having a wrap around also provides an ideal solution to increase the amount of natural light within your property. Leveraging the new wall surface area to incorporate large windows, or adding ceiling windows floods your home with sunlight.

This provides a sense of connected living, with a bridge between your home and garden. Wrap arounds are often used as an area combining the comfort of your interior with the fresh air of the outdoors.

These benefits mean that this extension is often used in denser urban areas where space is at a premium. It is a cost-effective solution for making the most of your layout and providing contemporary living with optimal space saving.

What are wrap around extensions used for?

Common uses of this sort of building extension include:

• Playrooms
• Conservatories
• Utility areas
• Relaxation spaces
• Open-plan kitchens
• Dining areas

The diverse nature of a wrap around means that there is a world of possibilities in terms of uses, finishes, build structures and layouts.

If your home has an attached garage to the side, you can either incorporate the garage into the extension or create a new room, such as a utility area, to lead onto your garage.

Pitched roofs with Velux windows are a popular choice, as an easy way to bring additional daylight into your new living space.

Other options include sliding glass doors leading out onto a deck or patio, to connect the indoors with the outdoors, or knocking through existing external walls to create a large open plan area throughout the lower floor of your home.

How much does a wrap around conversion cost?

The budget for your wrap around extension varies dependant on several factors:

• How large a floor space you have available to build on
• What height and width your extension needs to be
• How much structural work is involved
• Whether you choose to have external work completed as well (e.g. decking)
• Which materials and finishes you choose
• How many windows you select for your extension
• The costs of architects, planning and legal fees

Since so many of these variables are dependant on your home and design, the cost of a wrap around extension can start at around £40,000 up to £65,000 for a typical semi-detached home. A bespoke extension for a larger property may cost considerably more.

A good rule of thumb is to work based on £1,500-£2,000 per m2. Building costs in London and the South East will be at the higher end of the spectrum, and your choice of materials will make a big impact.

There are always cheaper solutions, however, we recommend that you use the best quality construction and finishes possible within your budget; your extension should be built to last for life, and a low-quality build will likely cost a lot more in the long term to maintain.

Extension cost factors explained:

1. Size of the extension

Every wrap around extension is tailored to the individual property. There is no one size fits all solution, and the size of your extension will depend on the space you have available, how much floor space you wish to build, and what constraints there are in terms of accessibility.

Wrap around conversions are a great choice when you do not have a large garden, or wish to preserve as much outside space as possible.

Measure out where you would like your walls to extend to, to get a good idea of the m2 of your build. Remember that external walls, insulation, inner panels etc. will all eat up some of that space, and so your internal floor space will be reduced by the size of the building materials used.

Another factor is whether your extension is the single height or double height. Many wrap arounds are single height, but you have lots of options when thinking about the design.

Double height extensions can provide an additional upper level, either across the extension or along one side. A popular choice is to build an office area on an upper level at the side of the property.

It can also be a way to create a vaulted ceiling and an extension with an elevated height for the ultimate in contemporary design and spacious living.

2. How much glazing your extension incorporates

Building a new extension is a prime opportunity to bring more light into your home. Natural light is proven to be beneficial to our health, well-being and happiness – so having more sunlight reaching your home is often a key reason to think about building an extension!

Choosing the glazing for your extension will depend on the intended purpose of the space. Think about:

• Whether you intend to have sliding glass doors – these will be external, so need to be properly safe and secure
• How many windows you would like to have, and how large they should be
• Whether you need any specialist glazing for complex building shapes or sizes
• How your home is orientated, and in which direction it faces to decide where glazing will make the most of natural light
• Whether you would like to include Velux or roof windows

Given that your external glazing will be exposed to the elements, it is important to choose robust windows that will provide security, protection from the weather, and insulation to keep your home energy efficient.

If you aren’t sure which sorts of glazing will be right for your extension or will fit in seamlessly with the period or aesthetic of your home, ask for a consultation in advance of making any decisions to review the choices out there.

3. Whether structural work is required

Building outwards from your home might be simple, or it might not be! This variable is one of those factors that can double your budget, so if you are in any doubt make sure to ask for some professional advice including a site visit to check how extensive the structural work may be.

Structural work can involve any changes to your existing walls or steelwork. If you plan to remove one of your existing external walls, you will need to include these costs. Make sure to budget for structural enforcement for those new spaces, such as RSJs and lintels.

If you live in a densely populated urban area, it might be tricky for construction vehicles to reach your home, and need some creative solutions for locating a skip on site, or moving equipment around.

Any changes to your drainage, piping or gas meters will need to be considered, so check which utilities run through areas impacted by the extension build, and think about whether any meters need to be relocated. You may need additional permissions or planning to move pipework.

Soil types vary across the UK, so your builder might need specific materials or equipment to create a stable foundation on your existing outdoor space.

Another oft-overlooked factor is trees! If there are any established trees in your garden that would be impacted by the extension, check whether they are protected by a Tree Protection Order (TPO). You may need permission to remove or cut back a tree and might need to contract a tree surgeon to carry out the work safely.

4. The cost of professional services

Professional services are an important consideration when thinking about a build cost budget. Whilst we always think about building costs and planning permission, there are several other professionals whose services you may require:

• Structural engineers
• Planning fees
• Architects fees
• Tree surgeons costs
• Legal fees – particularly if your extension impacts a common boundary

5. Your choices of materials and finishes

The world is your oyster when choosing what your extension should look like! If you are using an architect, they should ask for your ideas and inspirations to come up with a design that fits your specification, whilst being sympathetic to the existing property.

Decisions to make include:

• Building construction – the outer walls could be made from blocks or brick, have a tiled, rendered or panelled exterior
• Roofing – you could choose a flat roof, a pitched roof or a double-height extension and will need to choose what sort of finish, tiling or panelling you would like
• Doors & windows – uPVC is a popular choice since it is energy and cost-efficient, but you may choose custom glazing or bespoke frames
• Insulation – to prevent drafts and retain energy efficiency you could choose fibre, foam or extruded PVC insulation
• Internal fittings – these include everything from the finish of the walls and ceilings, electrical fittings, doors, flooring and utilities such as taps and gas pipes

For homeowners who have a side garage, why not read more on the cost of garage extensions as an alternative to a wrap around extension.

Frequently asked questions

How long does a wrap around extension take?

If your wrap around conversion has been well planned, and all the relevant permissions are in place in good time, the build will be much smoother. A simple extension usually takes around three to four months in construction time.

Should your extension be more complex, be large, or incorporate a double-height conversion, the construction time is likely to take closer to six months.

Taking into consideration the time taken for planning applications to be processed, and the time to design the extension and make decisions on materials, a good timescale for the total extension project is around one year.

Do I need planning permission?

Whether or not you need planning permission will depend on the size of your existing home, and the planned size of your extension.

If your extension is small in comparison to the home, you may be able to build without explicit permission under permitted development (PD). Make sure to check the most up to date rules before proceeding with a build, just in case any of the eligibility criteria for PD have changed!

The following criteria allow an extension to be built without planning permission in England:

1. The total area of buildings, including the extension and any previous additions, do not exceed 50% of the total area of land around the original property
2. The extension is not extending towards the front of the property – the extension cannot extend to the side if your home faces a road or highway
3. A single-storey extension is not extending out towards the rear of the property by more than 3 metres for terraced or semi-detached homes, or by more than 4 metres for a detached home
4. The side extension is single storey and no more than 4 metres high and is no wider than half of the width of the original property
5. If your extension reaches within 2 metres of a boundary, the maximum height of the eaves may be no more than 3 metres
6. If your extension includes multiple stories, the eaves and ridge of the roof may not be any taller than the existing property and must have a matching pitch of the roof
7. If your extension includes multiple stories, this may not extend beyond the rear wall of the existing property by more than 3 metres, or reach within 7 metres of a boundary opposite the rear of the property
8. Windows in an upper floor on a side elevation must use obscure glazing, and either be non-opening or be at least 1.7 metres above the floor
9. External materials must be similar to those used on the original property, excluding conservatories

Whilst these rules sound fairly complex, remember that they are only reasons why planning permission is not required. If you aren’t sure whether or not to apply, seek advice before beginning any work and ask for confirmation from your local planning authority in writing to avoid any future problems.

Exemptions from planning permission do not apply to listed properties, and in that case, Listed Building Consent will be required.

How much does a planning application cost?

Typically, the planning application process takes around 8 weeks and up to 13 weeks for more complicated applications.

The cost of a householder application in England, which covers extensions, is currently £206.

What are the planning stages of a wrap around extension?

The steps to planning for creating your dream extension include:

1. Initial planning: assessing your plot of land, the structural integrity of your property and assess how much room you have available to build on. Deciding on the size and scope of your extension, and what purpose it should serve.
2. Designing: creating a floor plan for your extension, and making choices about layout. This stage includes checking whether you will need planning permission and seeking any other consent.
3. Appointing contractors: choose your contractors carefully, and ensure that you receive 3 x quotes for every piece of work to ensure you are getting good value for money. Confirm with each contractor the scope of work, and identify where additional tradespeople or professionals will be required to cover work not included – such as laying pipework or gas lines.
4. Site preparation: many people choose to live off-site during an extensive build, but it can be possible to remain at your home whilst work takes place. Make sure the access has been agreed, the times and days of work are planned and shared with your neighbours, and any furniture or fittings that you have agreed to remove before work have been cleared.

What is the build process for constructing a wrap around conversion?

Usually, the build will be split into several stages. It is best to agree on these stages in advance and set timescales for each to ensure that your extension build is running to schedule and remains on track.

Stage 1: Preparation and Groundwork
This prepares the structure for the build to start, such as clearing access to the site, delivering raw materials, laying foundations and installing pipework.

Stage 2: Superstructure & External Walls
This is where the frame of your extension starts to take place! Lintels will be put in place, blockwork and brickwork begin, cavity wall insulation is fitted and the door and window frames are put in place.

Stage 3: Internal Walls & Roofing
The internal walls are now added to the external framework, and the roof structure is erected.

Stage 4: Roof Covering, Windows & Doors
Now the gaps start to be filled! The roof structure is completed with battens, tiles, facias and soffits. Windows and doors are fitted into the frames, and guttering and pipework are installed.

Stage 5: First Fix & Plastering
The ‘first fix’ is where initial plumbing, carpentry and electrics are installed. Internal walls are then ready to be plastered and left to dry for some time before they can be touched.

Stage 6: Second Fix & Flooring
Once the plaster is dry, the ‘second fix’ takes place, where electric sockets are made live, switches are fitted and connections completed. The flooring can now be laid, and the decorating begins.

Stage 7: Snagging
Don’t forget about snagging! Once the work is complete, it is essential to take the time to check every aspect of the build, and identify any niggles, finishes that aren’t perfect or any changes required before the build is marked as complete and becomes due for final payment.