Over the past few years, interest in house extensions has been on the rise, as you can see from the Google Trends data below. Fittingly, there are a wide range of reasons why someone might want to extend their house. Some reasons include accessibility, wanting more living space, wanting to update the home’s appearance, needing more space for a growing family, or you want to update your home to make it more energy-efficient.
Whatever the reason, an extension can be a great way to improve your home; however, there are a few considerations you need to be aware of before jumping into a house extension project.
In our guide to planning house extensions, you will find answers to a range of commonly asked questions:
- What to consider before you start a house extension?
- What is the process for extending a house?
- Building a house extension: where to start?
What to consider before you start a house extension?
There are a few things you will need to consider before you start your house extension project.
Your surroundings
The surroundings of a house can have a significant impact on the design of an extension.
Trees, soil type and other environmental factors
For example, if the house is surrounded by large trees, then it may be necessary to design the extension with a higher roof to avoid blocking the sunlight.
Alternatively, if the house is located on a hill, then the extension may need to be designed with a lower profile to avoid being visible from below. In addition, the type of soil can also affect the design of an extension. For example, if the soil is very sandy, then it may be necessary to use a foundation that is more resistant to erosion.
Property size and type
When planning a house extension, you will also need to consider factors such as:
Neighbours
Do you share a wall with your neighbour? Even if it is a garden wall, you might have to consider third-party wall rules; find out more at the gov.uk website.
Also, if you are considering a large extension that would take up a significant amount of your property, you should speak to your neighbours to see if they would be affected by your plans. If your extension would obstruct their light, air, or view, they may be able to object to your plans.
Listed properties
There are various restrictions for construction work for listed properties; find out more by reading our guide on listed buildings.
How long do house extensions take?
Building a house extension can be a costly and time-consuming process, so you will need to make sure you are fully prepared for it.
In addition, the impact of post-Brexit and Covid-19 pandemic material shortages and logistics issues whilst building a house extension are likely to be significant. According to Financial Times and HomeBuilding.co.uk, the availability of building materials and labour is reduced, which is likely to lead to considerable delays in construction projects and increased costs.
The length of a house extension project considerably depends on a few factors:
- The size of the extension
- The complexity of the extension
- The time of year (winter projects tend to take longer)
- The availability of architects & building engineers
- The availability of contractors and building supplies
- The time it takes to get planning permission (if required)
- The time it takes to complete the building work
Generally, house extension projects can take anywhere from a few weeks to a few months, depending on the factors mentioned.
Costs of house extensions
There is no definitive answer to this question as the costs of house extensions will vary depending on the size and complexity of the extension, as well as the materials and labour costs in your area.
Typical costs for a house extension:
- Architect fees
- Structural engineer fees
- Builder fees
- Interior designer fees (optional)
- Project manager fees (optional)
- Furnishing your house extension to its intended use
- Amending pavement or driveway (if applies)
- Material costs
- ‘Building control body’ (BCB) fees
- Insurance costs
How much does an extension add to the value of a house?
Again, there isn’t one definitive answer to this question that would fit a variety of different houses. The amount of value that a house extension would add to the overall value of the property is impacted by the type of extension that is being built, the location of the property and the current market conditions.
Generally speaking, an extension can add anywhere from 10-50% to the value of a house, depending on the aforementioned factors.
Take a look at the selling prices of houses in your area vs houses with an extension or speak to a local real estate agent to get a clearer idea of how much value an extension would add to your house.
What is the process for extending a house?
The process for extending a house can vary depending on the size and scope of the extension, as well as the planning regulations in place.
In general, homeowners will need to submit a planning application to their local council, which will then be assessed to see if the extension is feasible and meets all planning regulations. If the extension is approved, homeowners will then need to hire a builder to carry out the work.
Acquiring appropriate permissions for the house extension
In order to build a house extension, it is likely that you will need to acquire a building permit from your local municipality. The specific permissions you will need will vary depending on your municipality; learn more about planning permission requirements on the Planning Portal or consult your local building authority.
Insuring house extension before construction
There are 3 main reasons why you might want to insure your house extension before it is constructed:
- Insure existing house structure during home extension project
First if something were to happen to your home during the construction process, you would be covered. Furthermore, prior to starting the construction process, ensure that your insurance policy will not only cover the existing structure (what is already built) for the usual perils of subsidence, flood, damage, theft, storm etc. but also ensure the existing structure is covered from any damage caused by or arising from, activities of the contractor(s) on-site.
2. Insure the new extension itself
Second, if something were to happen to the workers or the construction materials, you would be covered. This ensures the new structure is covered should anything happen during the period of construction. This extends to include materials, for example, any damage to the marble kitchen countertop on-site or during transit, providing additional peace of mind.
3. Any liabilities connected to the work
Lastly, another reason why you should insure a home extension project is to cover any liabilities connected to the work. For example, if the contractors on-site accidentally damaged the neighbour’s wall or installed a new roof and the tiles fell off and injured someone, you’d be covered for costs associated with these damages. The home extension insurance assures that you have public and owner’s liability covered during the period of the works.
Depending on your chosen insurer and insurance needs, you can discuss the appropriate insurance product for your home extension project.
When should I let my insurer know about my house extension project?
We recommend contacting your insurance provider at the planning stage of the project before the actual contraction work starts as most insurers will not cover you if you contact them halfway through the construction. You should contact your insurer as soon as you have signed off the plans, agreed on the budget and have an estimated start date of the project. This gives you every chance of ensuring you can get an appropriate cover ahead of time.
Builders say that they have insurance. Is that enough?
Simply put – no, it is not enough. Ensure that your property is covered by contacting our insurance professionals for advice on home extension insurance.
Building a house extension: where to start?
Designing the house extension
Before we get to the dirty work, let’s take a step back and brainstorm!
Intended use
Firstly, you will need to think about what you want to use the extension for – do you want an extra bedroom, a playroom or a home office?
Exterior and interior design
You will also need to think about the design and layout of your extension. Will it be a single storey or two storey extension? Will it have a roof or be open to the sky? Will it be attached to the main house or be a separate building? Depending on the type of your extension, it is likely that you will need to get building plans drawn up and submit them to your local planning authority for approval.
Assemble the dream team
After the initial brainstorming about the spatial requirements and usage, it is time to call in the specialists to design and execute your dream house extension!
Architect
The first step in designing a house extension is to hire an architect. An architect will help you design your extension and make sure it is compliant with all building regulations.
Structural engineer
When hiring a structural engineer, it is important to ensure that they have the necessary qualifications and experience to carry out the work. Ask to see examples of their previous work and get referrals from friends or family members who have used their services in the past.
Builder
If you are hiring a builder to design and construct your house extension, it is important to find one who you can trust to do a good job.
Here are some tips for finding the right builder:
1. Ask family and friends for recommendations.
2. Check with the local builders’ association for a list of qualified builders in your area or get in touch with the National Federation of Builders who can help you choose a licensed builder in your area.
3. Get quotes from several builders and ask for references.
4. Meet with the builders and ask them questions about their experience, how they will approach the project, and what type of materials they plan to use.
5. Ask to see examples of their previous work.
6. Read reviews of local builders online; you can do this using various online tools, including Trust A Trader or TrustPilot.
7. Make sure the builder is insured.
8. Sign a contract with the builder detailing the work to be done, the materials to be used, and the payment schedule.
Interior designer
When you are hiring an interior designer, you need to make sure that you are hiring someone who is qualified and experienced. You should ask to see examples of their work, and you should also ask them for references.
An experienced interior designer can help you to choose the right furniture and accessories. They will also help you to plan the layout of the extension, and they will make sure that it is both functional and stylish.
Project manager
If you are hiring a project manager, they will help you design the house extension. They will work with you to create a plan that meets your needs and is within your budget. They will also help you stay on track during the construction process. To lower the costs, you can act as your own project manager if you feel capable of doing so.
Working with specialists to carry out the house extension project
Once the plans are drawn up, a specialist team assembled, permissions acquired (if necessary) and insurance policy updated, it is time to start work on the construction of the house extension project!
A tip from us is to always plan for extended deadlines. With the uncertainty of delivery times and supply chain issues, it is better to have your expectations managed early on.
We hope that this guide to house extensions will shine some light on the various considerations you should be aware of when planning your house extension. For more information on house extension insurance, visit our house renovation and extension insurance page or call our friendly insurance specialist team on 01730 777600.
