Side Extensions London

Adding more space to your home is a good way of meeting changing needs and avoiding the upheaval of moving house. The benefits are long term too, as the extra room or rooms will also add value for when you eventually do decide to sell and move on.

Although a loft conversion, rear extension, or perhaps a ground and first floor extension, are the types of alterations that spring to mind, it’s also worth considering a house side extension – taking advantage of otherwise difficult to use space, with the added gain that you won’t be eating into a valuable area in your garden. 

Single or double storey side extension?

Whether you opt for a single or double storey extension is ultimately a subjective choice, but it will be influenced by a number of factors, including

• Your overall budget. A double height extension will cost more (although with a lower average cost per m2) but will add more long term value to the property
• The amount of extra space you want,  and what you want it for 
• If the side extension is over two floors and is wide enough, you may be able to have it as a self-contained annex, for rental or for an older relative
• Often, side extensions in London are used to enlarge a kitchen or kitchen, and dining area, but they can also be used to create a home office or downstairs bedroom. By making the side extension double storey, you will then have the extra flexibility of enlarging a bedroom, adding an ensuite bathroom, or creating a completely new additional room – or two.

When weighing up your options don’t be afraid of your imagination or taking advice. An experienced architectural designer is used to exploring all permutations and can often see ways to use a space that does not occur to the homeowner.

Structural change is an opportunity  

The most important thing about a side extension is that it becomes an integral part of your existing property.

Don’t confuse a house side extension with a “lean-to” of the homemade variety, which is more like a shed stuck to the side of a house. A professionally designed side extension allows you to open up your house along one side, increasing natural light as well as space.

Use structural changes to let the light in

Rather than use the side extension to ‘bolt on’ another room or two, it is usually better to open up the side of the property.

This gives you more flexibility in how you use the space and many more options for the size and location of windows. There are many semi detached house side extension ideas that you can apply to your extension which will allow you to maximise the space while working on a small lot. 

‘Knocking through’ in this way will alter the structure of the building. In particular you are changing at least one supporting wall, so you need the services of a structural engineer, to advise on a supervise this element of the work.

Early preparation pays off

When you have a reasonably clear idea of what you want, it will help to get the advice of a professional. Good architectural designers will be able to take your ideas and combine the best practical considerations with a sense of style and sensitivity to the existing building – your home.

A feasibility study at this stage will help you understand how to achieve your aims to get the best results and keep control of your budget. They will understand the construction issues as well as the design criteria. Aim to commission a firm who are Planning experts. This will mean  the same professionals having oversight of the whole process, including project management if that matches your needs. 

When the essentials of the project are agreed, your architectural designers can commence working on the detailed planning and preparation for your side extension. This will include the specifications and paperwork that goes with a Planning Application or Permitted Development Rights, whichever is appropriate.

Give some thought to your neighbours

Any side extension is likely to impact on your neighbours in some way. You’ll need to consider this at an early stage to avoid loss of goodwill and any potential action they may take to disrupt your plans if they are not happy with the intended work. 

Be ready for a Party Wall Agreement

If your side extension abuts or is near to your neighbour’s property you will need a Party Wall Agreement to formalise and record the agreed work to be done.

This would include excavation work (eg for new foundations) within 3 metres of the boundary, even if there is no physical contact with their property. Your architectural designers will advise whether a Party Wall Agreement is necessary and they may be able to recommend a party wall surveyor who can take charge of this element.

Avoid overshadowing your neighbour

Your neighbours also have a right to light, and this may be infringed if your side extension is large enough to overshadow their property or block light. It’s best to address this possibility early on: even when you have Planning Permission or a Lawful Development Certificate, your neighbours can still object if they consider they rights have been infringed. New buildings – ones less than 20 years old – may not have this right, but it is always best to check and take expert advice.

Do I need Planning Permission for a house side extension?

As often with this question, the first answer is ‘it depends.’ Fortunately the rules and guidelines are clear in principal. However, with Planning Permission, different local authorities (even those with similar Planning policies) interpret Planning legislation to best suit their own context. It’s always worth getting the advice of a Planning Specialist. Above all, don’t jump to conclusions and start work before you are 100% sure of your own situation.

You may have Permitted Development Rights

Permitted Development Rights were introduced to provide a presumption in favour of modest alterations – small extensions and simple loft conversions, for example – and to streamline the bureaucracy around Planning Permission. Rules around Permitted Development Rights are well established and a local authority can’t prevent permitted development if your project comes within the national criteria.

There is more information about Permitted Development Rights on gov.uk and the Planning Portal. These provide useful guidance, but it is either quite general or very technical; it is still best to have the advice of an experienced professional so you can avoid costly mistakes.

If you have permitted Development Rights, get a Lawful Development Certificate

Getting this certificate from your local Planning authority is important. It will give you peace of mind, especially if anyone challenges the work once it’s under way. Additionally, when you come to sell it will be proof that Planning Permission was not required. The fee for this is currently £103 and it is money well spent.

If you need Planning Permission, enlist the help of an expert

Although it is possible to apply for Planning Permission by yourself, doing so comes with many obstacles. In particular, the law and regulations can be quite nuanced, so it is easy to trip up if you are inexperienced. It’s better (and more cost effective) to have the help of a Planning Specialist who can prepare and make the application on your behalf. 

Another reason to  apply for Planning Permission is that, although the process is more lengthy, you may find you are faced with fewer limitations as to size and style of construction

What about conservation areas and listed buildings?

Planning Permission and Permitted Development Rights will very probably be different if you live in a Conservation Area, Area of Outstanding Natural Beauty or World Heritage Site. 

If your house is listed (some streets in London are listed in their entirety) , then you will need Listed Building Consent along with any other permission or right.  

In all these scenarios, it’s best to secure the advice and support of an architectural practice which knows your area well.

Side extensions in London are a speciality

Divi Design are Architectural Designers and Planning Specialists, with in depth experience of all forms of extensions and loft conversions in London housing. We know the London boroughs well, and have excellent professional relationships with Planning Officers across the city. We have an excellent track record with Planning Applications and on guidance around Permitted Development. 

We love the satisfaction of completing a side extension and knowing we have significantly improved someone’s home and their quality of life too. We enjoy the intricacies of designing and project managing side extensions, delivering maximum benefit from the space available.

We do house extensions all over London. Areas include (but are not limited to): Barking & Dagenham, Bromley, Barnet, Bexley, Enfield, Greenwich, Hammersmith & Fulham, Havering, Romford, Thurrock, Twickenham, Waltham Forest, Wandsworth, Walthamstow, Richmond,  High Wycombe, Harrow, and Ealing.