Starting a successful home extension project can be daunting. That’s why we’ve outlined some practical tips for you to think about during your home extension project.
If you’re building over or near a Thames Water sewer that is classified as ‘Public’, you will likely need to submit relevant drawings and details to apply for a Build-over agreement. Link to more information on a TW build-over here. Or…let us deal with the lengthy application process and deal with Thames Water on your behalf. We do this as a standard for all our clients. TIP: Complete a CCTV drainage survey for less than £300 to fully understand where your drainage runs and what condition your drains are in. The image below shows tree roots that have broken into the drainage pipe. This could cause costly blockages if not dealt with.
20-25% of your budget is likely to be spent in the ground, so pay the time upfront thoroughly assessing what type of soil you have so that there are no surprises! The soil type will affect the depth and costs of your foundations. Don’t panic, as we work with talented and trusted engineers to give you the best advice for a successful home extension.
Trees absorb groundwater and can affect the shrinkability of the soil surrounding your house. This can negatively affect your foundation design and may require deeper foundations, adding extra cost.
For example, Leylandii trees in London clay soil can require up to 2.5m deep foundations (instead of a typical 1m) and, in specific scenarios, make trench foundations unfeasible. We will spot any potential constraints during our initial Home Design Consultation and advise on the best solution for you. TIP: Spot nearby trees and identify them at the design stage. Click here to place your type of tree for FREE using this helpful app by the NHBC.
Period and older properties will often bring unexpected costs and uncover hidden problems that are unforeseen. If you are carrying out building works on older properties, ensure you have a healthy contingency in your budget. We’d suggest 15% as a minimum for a successful home extension project.
This is where a sound engineer can save you money. There will be many ways to design your supporting structure. A good engineer will design a lean scheme due to an easy installation on-site and good detailing in conjunction with your architect. That all sounds very ‘techy’, we know. That’s why we work closely with engineers that we understand design with your budget in mind and don’t over-engineer your scheme. TIP: Always ask your engineer to suggest cost-saving measures. Installing a brickwork pier instead of a steel post could save you £££’s and not change the look and feel of your house extension. Ask us how!
Your procurement method is another topic in itself and relates to the way in which you set up the project. This will depend on the level of project management you wish to undertake yourself, the level of risk you want to take personally, your type of building contract, and many other factors which will form the topic of another useful article from Aura Homes. TIP: Don’t accept a builders quote via email! Start a project with a signed building contract between you and your builder/contractor. We will generally recommend the most common form of building contract in the industry – a JCT Contract. Your procurement method is another topic in itself and relates to how you set up the project. This will depend on the level of project management you wish to undertake, the level of risk you want to take personally, your type of building contract, and many other factors.
Start a project with a signed building contract between you and your builder/contractor. We will generally recommend the most common form of building contract in the industry – a JCT Contract.
Having a good relationship with your neighbours can keep your project moving swiftly, especially when your works require Party Wall Agreements. Briefly, these are needed when you are building close to your neighbour’s property or putting steel beams within a wall shared by you and your neighbour (known as a Party Wall). More information can be found here.
You have legal obligations as the homeowner under the Construction Design and Management Regulations (CDM) 2015.
Your contractor will need to be aware of these as they will have the most significant responsibilities during your build project.