What does it cost to extend your home?

 

We’re often asked how much a house extension costs in London. Extending the home is a popular option among clients who perhaps need another bedroom, an office space, or a living area, without the hassle (and stress) involved with moving house. Although home extensions in London generally cost more than elsewhere in the UK, they remain a viable and cost-effective option to create your ideal additional living space and increase the value of your home. In this post, we set out the main costs associated with a house extension project.

How much does it cost to extend your home

Harvist Road Glazed Envelope

Extending into the garden and optimising natural light

You generally have three options for extending your home: single storey, two storey or basement. The construction cost of extending the ground floor of your home (in a single storey) is, as a general rule, between £2,200 and £3,900 + VAT per square metre, depending on the level of the specification you decide on. This is a popular option for extending into the back garden to add a dining area, studio or additional living space. It is also an excellent way to bring more natural light into the property, with the ‘glazed envelope’ (like the one in the above image) making the new space feel very spacious and ‘open’. If you plan to use the new space for a kitchen or bathroom then the cost of the fitting will need to be included (typically expect an additional £10,000 + VAT for a kitchen [low-mid level of specification] or £5,000 + VAT for a bathroom [mid range]).

The value of two floors

A two-storey extension generally costs an additional 50% of the construction cost of a single storey extension. It gives you the option of adding an upstairs bedroom or other room and the investment will seem like good value as once the foundations and other structural supports are in place, you do not need to bear these costs again for the second storey. It is important to note that a two storey extension may impact on the amount of light reaching your garden and may also present additional complexity in the planning process (achieving consent for a two storey is often more difficult that for a single storey and sometimes not permitted at all for example in a Conservation Area).

Going underground

A basement addition tends to be the most expensive option per square metre because of the structural and construction complexity and risk. The construction cost of a new space in your basement in London is likely to amount to between £4,000 and £5,000 + VAT per square metre. The costs may be less if you have an existing basement which may instead need converting or extending partially.

Other costs to consider

In addition to the estimated costs set out above, you will also need to factor in the cost of the professional services that you require, such as an architect and any other consultants that you need to involve – for the majority of projects you’ll need a Structural Engineer, Party Wall Surveyor, Building Control Approved Inspector and sometimes a Mechanical & Electrical Engineer as well as a Quantity Surveyor. This typically adds 15-28% to the construction cost. There are also planning fees (£200 to £300 for a house extension, although some extensions may fall under Permitted Development Rights), home insurance costs, and VAT. The costs of windows, doors and central heating will also be in addition to the costs already listed.

Site access and other constraints

There can also be costs associated with mitigating the constraints of a site. For example, the soil type may affect the type of foundation required or the types of building material that can be used, or there may be trees, drainage or other pipework that need to be (re)moved to allow access. If your property is listed and/or situated in a conservation area, you will need to allow for higher costs overall.

Despite the long list of costs, a home extension can greatly improve your living space and also increase the value of your home by 10% to 30%. We take pride in the home extensions that we have completed for our clients and it is always a pleasure to bring more light and space into the home. You can browse some of our recent residential projects here. If you would like to discuss a potential project with us, please get in touch.

What is green infrastructure?

 

Our green spaces are under increasing pressure as the climate and population change. There is a continued demand for housing and, as a result, there has been a tendency to replace green areas in towns and cities with bricks and tarmac, particularly on driveways and in gardens. When it rains, increasingly heavy rainstorms land on smaller areas of permeable or well-drained ground, making roads and homes more prone to flooding than previously. ‘Green infrastructure’ is a term used to describe all of the green spaces in and around towns and cities. This might include parks, private gardens, agricultural fields, hedges, trees, woodland, rivers and ponds. In this post, we explain the concept in a little more detail and share some examples of green infrastructure projects in London.

green-infrastructure

Development of the term

‘Green infrastructure’ is a description of what the land is, but it also describes what the land does. The term reflects a growth in understanding of the various benefits that are to be gained from providing and maintaining healthy green spaces: reducing flood risk; improving psychological health and well-being; boosting local economic regeneration, and providing a habitat for wildlife. Rather than valuing green spaces for a specific use (e.g. a football field for recreational purposes), green infrastructure recognises that green space can provide a variety of functions, often at the same time.

Green infrastructure in England

The National Planning Policy Framework (NPPF) defines green infrastructure as “a network of multi-functional green space, urban and rural, which is capable of delivering a wide range of environmental and quality of life benefits for local communities”. The NPPF places the responsibility with local authorities to plan strategic green infrastructure networks, particularly to reduce the risks associated with climate change. Places where there is limited access to green space is also prioritised, as is the inclusion of green infrastructure in major development and regeneration schemes.

Green infrastructure in London

The All London Green Grid (ALGG) promotes green infrastructure across London. While London is already a very green city, with an existing park and green space network that functions well for recreational purposes, there is growing recognition of the need to plan, design and manage green spaces to provide additional benefits. Similarly, the London Infrastructure Plan 2050 emphasises that green infrastructure is as important for the city as other infrastructure such as roads and railway lines.

Recent green infrastructure projects in north and west London include the London Wildlife Trust’s new 11 hectare nature reserve, Woodberry Wetlands in Stoke Newington, which opened to the public earlier this year, and a new interactive map that allows you to explore the ‘Wild West End‘ of the capital. The aim of this project is to create a network of green spaces and green roofs between the major parks in the West End of London.

To learn more about green infrastructure and other local and national projects, visit the Green Infrastructure Partnership website.