8 practical tips for a successful home extension project [2019]

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 it all starts to get too much…get in touch on 0203 189 1619

1. Drains – It’s not pretty, but understand them fast

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 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 in to the drainage pipe.  This could cause costly blockages if not dealt with.

CCTV drainage

2. What’s in the Ground?

20-25% of your budget is likely to be spent in the ground so spend the time upfront fully 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 that will give you the best advice for a successful home extension.

TIP:  If you are completing a basement extension you will need to undertake full soil investigation tests, and find out where the ground water level is so that your structural engineer can design your foundations to suit.

3.  Nearby trees can play havoc with your foundations

Trees absorb ground water 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.

Leylandii trees in a London clay soil close to your proposed extension can require up to 2.5m deep foundations (instead of a typical 1m) and in certain scenarios make trench foundations unfeasible.

During our initial Home Design Consultation we will spot any potential constraints and advise on the best solution for you.

TIP:  Spot nearby trees and identify them at design stage.  Click here to identify your type of tree for FREE using this useful app by the NHBC

4.   Age isn’t just a number when it comes to property – it can cost you £££’s

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.

TIP:   Ensure you carry out a full structural survey of the property as early as possible so that you can budget for issues.  Find out more on the Royal Institute of Chartered Surveyors (RICS) website here.

5.  Think practically and save £££’s on your structural design

This is where a good Engineer can save you money.

There will be many ways to design your supporting structure, and a good engineer will design a lean scheme with due regard 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 know 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 you house extension.  Ask us how!

6.  Set up your project right from the start with a Building Contract

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.

Too often clients think they are saving money by stopping the architects services after the design/drawing package stage – this is misinformed!

Bonus TIP:  An architect employed as Contract Administrator overseeing the construction work will be the intermediary between you and the builder (removing the hassle from you!).

Not only will the architect make sure the builder is completing the project as per the design,

and sign-off staged payments based on the amount of work completed, but…

Architects will also suggest ways throughout the project to save money,

add value with new design possibilities,

and increase the likelihood of your project being on time and within budget.

7.  Be friendly to your neighbours – they could stop your progress for months.

Having a good relationship with your neighbours can keep your project moving swiftly especially when your works require Party Wall Agreements in compliance with the Party Wall Act 1996.

Briefly, these are needed when you are building close to your neighbours 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.

TIP:  Employ a Party Wall Surveyor to serve a Party Wall Notice on your neighbour as soon as possible.  The initial notice should cost no more than £150 +VAT.

You can serve this yourself, but if the correct notices aren’t served this could hold up your project.

Bonus TIP:  Leave it to the professionals.  We will organise this for you.

8.  It’s not fun, but it does save lives – Health and Safety

You have legal obligations as the homeowner under the Construction Design and Management Regulations (CDM) 2015.

CDM Health Safety Guide HeaderYour contractor will need to be aware of these as they will have the greatest responsibilities during your build project.

TIP:  Incorrect H&S on site can cause delays and even fines so ensure your contractor has sufficient cost in his tender to fulfil his duties.

Read our blog here on this topic….or…

Let our experienced team of professionals guide you through your project!

Thanks for reading.

If you have a project you’d like to discuss, please Create Your Brief now and we’ll be in touch.

 

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Ben Richards
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