The benefits of building an extension are numerous, and SCM has years of experience working with a wide range of building and construction stakeholders to ensure that, when an extension is built, those benefits are fully realised.
An extension may sometimes seem like a short term cost, but it reaps long term rewards, whether that takes the form of added space for occupants, a modernised infrastructure, or simply adding value to a property. There are a number of extensions which can instantly add value to a home, and bring a property owner a significant return on their investment. Here are the five which recent surveys and studies agree can reap the most benefits.
According to a number of sources, including Nationwide building society, a loft conversion can add as much as 21% value to the price of a property. By Nationwide’s own estimate, a property worth £300,000 would increase in value by £63,000. Of course, it’s important to bear in mind that the cost of such a conversion would become less worthwhile on a significantly cheaper property, since the average cost of a loft conversion can be anywhere from £30-40,000.
An estimate from the website This Is Money puts the added value of an extra bathroom at 5% of the price of the property; meanwhile an upgrade to an existing bathroom could add as much as 3%.
Added floor space
This can add up to 11% value to a home, but it’s also worth bearing in mind that this can be a costly extension, especially in London and the south east. For example, a basement extension in London can cost as much as £250 per square foot.
An Extra Bedroom
The Nationwide study in 2014 estimated that an extra bedroom could add as much as 10% to the value of a home.
A conservatory can add as much as 10% value to the price of a home, and can complement the existing structure of a property if done right.
SCM has worked with clients, contractors across the public and private sectors, for both commercial and domestic purposes. We’ve put together a step by step guide on the most viable way of ensuring your extension goes smoothly, including advice on how to ensure you stay within budget, and how to ensure you’re making the necessary logistical preparations in advance of any renovation. Click on the five chapters below for a comprehensive guide to the challenges, rewards and pitfalls of undertaking a housing extension.
How much does it cost to build an extension?
There’s no one size fits all approach to this, as estimates and quotes will differ depending on the type of project, and on the locality. But the average cost of a house extension in 2017 is now placed at £1,500 per square metre by a number of other industry guides and experts, with the cost per square footage rising as high as £2,500 for more complex builds. And this is excluding the additional 10-15% cost for professional fees and VAT.
It may also be useful to think of extension costs in terms of the number of storeys you plan on adding in any given scenario. Again, it’s impossible to give a completely authoritative estimate, when every extension build is different.
However, based on the price per square metre, and local house prices, estimated costs for any given extension can be any of the following:
- A single storey extension could cost from £39,000 to £65,000 for more high-end properties/London based properties (inclusive of professional fees and VAT)
- A double storey extension will, as a rule, normally add 50% to the cost of a single storey extension, as you’re going to be paying less per square metre. The overall cost of a double storey extension roughly costs between £45,000 and £76,000.
- A basement extension is a much higher spec job, and can cost as much as £4,000 per square metre for high end builds. This is normally because of the extra ground work necessary.
The overall cost of an extension will also depend on a number of other factors, depending on the type of building being renovated, and the nature of the renovation itself. These include:
- The type of existing building or structure (e.g. brick, glass, pre-fab)
- Demolition requirements.
- The current accessibility of the building.
- Changes to internal fixtures and fittings.
- Changes to existing infrastructure (e.g. drainage, ventilation)
- Alterations to the external appearance of a building.
How to plan and budget an extension
It’s a truism that planning and budgeting for a project with the size and scale of a housing extension is something that will require a lot of time and attention. Schedules need to be as realistic as possible, and costs kept firmly within budget if your extension is to go smoothly.
Assessing the building’s condition
This is a vital first step in any major renovation or extension project, as it allows you to gain a complete picture of the status of a property. Whether buying a home that you plan to renovate, or building an extension in your current dwelling, your first step should be to commission a survey and/or a building report. This will allow you to identify any problems which may cause further complications, including
- Damp or drainage problems.
Apply for Necessary Consent
At SCM Group, we’re experts at administering the logistics of any given construction or renovation project. This means we understand the vital importance of gaining any necessary statutory consent prior to undertaking an extension. Any schedule of work will need to take into account any relevant planning permission or party wall agreements with neighbours. Finally, you will require Building Regulations Approval to ensure that it meets minimum design and construction standards.
It’s worth bearing in mind the following:
- An extension is often a development which doesn’t require planning permission, subject to certain laws and limits. There are also different rules for flats and maisonettes.
- If you wish to build a large extension, you need will need to contact your local authority, who will then consult relevant neighbours to advise them of any planned objections or concerns. The decision then lies with the local authority if adjoining neighbours raise any concerns.
Depending on the type of extension, your project may start with an added advantage if your project is classed as a permitted development, which normally includes an existing garage or roof space.
Check for any grants/tax concessions
When starting out with your project, it’s worth checking for any relevant tax or VAT concessions for which you may be eligible. For example:
- VAT concessions on any landscaping or outside works covered by your planning permission.
- A reduced rate of 5% VAT if the extension is on a property that you can prove has been empty for two years or more.
There are also grants available for some types of restoration and home improvement work, at either a local or national level so it’s worth checking these before you start.
Financing your extension
When considering finance options for a renovation or extension, it’s worth bearing in mind that high street banks and lenders will only offer a mortgage for properties which are already classed as habitable, thereby excluding derelict or otherwise non-habitable properties. If the property is classed as in need of repair but habitable, it may be possible to secure a mortgage up to 95% of the current value of the property. However, these funds may be withheld, pending the completion of certain urgent repairs, including: damp-proofing, re-wiring or any major changes to the infrastructure of the building.
Additional funding options for an extension include:
- A home improvement loan secured against the value of your property.
- Increase your mortgage to release the necessary funds.
- A straightforward personal loan.
There are a number of practical steps that will need to be taken prior to beginning the main extension work. This will including clearing the existing site, planning main site access and layout, and making the building secure and weather tight.
Making the site secure
This will encompass both making the site secure from any outside hazards or risks, as well as ensuring the extension site has the necessary amenities to make ongoing work safe and successful. e.g. electricity and water supply. At this stage, it’s also important to make sure that the site is weather tight, as any forthcoming joinery or plastering work will need a dry environment.
This is also the point at which it may be necessary to clear any other demolition/clearing of hazardous materials, and dealing with outstanding health and safety issues (for example, asbestos removal).
Solving damp issues
Depending on the type of building you are completing work on, it may be necessary to deal with any existing damp problems. Older buildings made of materials such as brick or stone are especially susceptible to damp issues. Solving any damp issues will normally comprise two further steps.
- Dealing with any current signs of damp, be it rising damp, or penetrating damp in walls and ceilings. This can, more often than not, be achieved through non-invasive means such as improving ground drainage or improving ventilation.
- It may also be necessary to upgrade any existing damp proofing, and this may even be a pre-requisite of any successful loan/finance application.
Checking site access and service connections
It’s worthwhile checking site layout and existing service connections such as drains, as any extension may require their renovation and/or removal.
Early Work & First Fix
If the internal layout of the property is going to change, then this stage is when stud walls will be built, and any staircases, doors or windows. It’s also important at this stage to ensure that the existing building is protected from any renovations or extensions going on.
Doors and windows will be installed and glazed at this point. If installing new windows, it’s worth considering double glazing for increased energy efficiency.
Floor and ceiling work
This will, in itself, encompass a number of changes/additions to the infrastructure of the building. This includes pipes for hot and cold running water, as well as the necessary renovations for new gas mains, electrical cables, phones and Internet/Ethernet cables and the wiring for any alarm systems. This would normally be the point at which any additions such as under-floor heating would be made.
Walls and ceilings can then be plastered, and screed laid, if it is a ground floor extension. It’s worth factoring into your overall work schedule that screed can take between two to six weeks to dry out.
Second fix, decorating and final finish
Ideally, you will have left enough time for the screed and plastering to dry out. When this has been allowed to happen, it’s time for the second fix.
Tiling and Flooring
This is the point in the extension where fixed flooring can begin. (NB: any wooden flooring or ceramic tiles are best installed prior to any skirting boards; likewise this will make any new kitchen units or white goods easier to install.
Fixtures and fittings
The second fix will allow for the installation of any major fixtures and fittings. These include:-
- Light fittings.
- Phone and television points.
- Bathroom taps.
- Kitchen extractor hoods.
At this stage, any new boiling or heating system will also be tested and activated. Other installation at this stage will also include any skirting boards or handrails. Some aspects of the fixtures and fittings may be done before tiling and flooring, but we recommend laying any flooring first to make the process easier.
Painting and Decorating
Before doing this stage of the process, it’s also important to finish any sanding or filing, as painting and decorating will need to be done in as clean and as dust-free an environment as possible.
When painting and decorating is complete, you should be free to complete any further fixtures and fittings, such as laying carpet and installing any blinds or curtains.