House Extension

Add space and value to your home or business by building a house extension. We take an energy saving and fabric first approach to improving your home. Don’t move, just improve!

House exention

Permitted developments rights: Any works to enlarge, alter or improve a house must be sympathetic to the existing property.   This means the materials should be of a similar appearance to those already visible from the outside of the home, but they do not need to be exactly the same.

Permissions: Planning permission is not required to increase the size of your loft if you only extend it outwards from the plane of your roof by up to 50 cubic metres in a semi-detached or detached house (or 40 cubic metres in a terrace) – as long as you set it back, at least, 20cm from the eaves. It is not allowed to build a dormer facing the street, or to alter the roof under your permitted development rights, and materials used must be similar to those used in the existing house.

All timber garden structures, including garden sheds and summerhouses, are subject to the same planning permission rules as other types of more permanent outbuildings. With this in mind, the majority of new garden buildings won’t actually require planning permission to be installed; this will all depend on where you wish to put the building in your garden and if you should live in an area that has been designated as an Area of Outstanding Natural Beauty or similar.
Planning permission rules apply to our complete range of garden buildings, but providing certain criteria are met, and considered permitted development and can proceed without permission.  Contact us to discuss futher.

Permitted development rights: Unlike an extension, a conservatory does not need to match the materials of the existing building; otherwise it falls under the same planning regulations as any single-storey extension.

From Planning to Design to Build: We can handle all of the key stages to offer a fully managed service, reducing the stress of the entire process.

Sustainable Building Techniques: Reducing the carbon footprint is very much a priority when it comes to your house extension. We can help you to make the house extension as sustainable as possible and introduce you to some innovative building solutions and renewable energy systems to offer the complete service.

Do you need permission? If your project can be designed to fall within your permitted development rights, no planning application should be required. However, you do not have standard permitted development rights if you live in a conservation area, listed building or a flat. If you’re a leaseholder, you’ll also need to check whether your lease allows you to carry out the proposed works without permission from your freeholder.

Building a house extension: Your house extension must not exceed 50% of the original land belonging to the house, or extend more than three metres beyond the rear of the original house (or by four metres if it’s a single-storey extension of a detached house).

The Process for a House Extension

site visit

Site Visit

We visit your property or business to assess what is possible within your budget.

Tools for install


Based on the project plan our install teams will build your extension.

Extension Design

We can show you 2D and 3D designs of your extension.


Our fabric first principle in hand with renewable energy solutions means near zero energy bills.

Design Approval

We fully price the materials and labour and produce an itemised list.

Add Value Save Energy

Our extensions will add 10% to 30% to the value of your property and reduce your energy bills.

I had quotes from a number of renewable companies. I chose Wessex ECOEnergy because they were the one company who were enthused with the ethos and  principal relating to a more sustainable way of life. They were also the only company who walked their talk, both directors have Solar PV, Solar Thermal and Wood Burners with boilers. They were patient with my questions, and were happy to give answers and explanation time.
Their team of contractors work really well together, were always polite, and diligent in their work.

The quality of the work is of a high order. I would have no hesitation in recommending Wessex EcoEnergy to anyone, for renewable or any other domestic or commercial project.

Charles Merivale

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