National Self Build & Renovation Centre Logo close Menu
Book Free Now

Design and specification

During this stage it will start to feel like your plans are really coming together, and you’ll have a good idea of what your finished home will look like. However, there are still a huge range of options to consider and decisions to make.

Self Build Design and Specification

You’re set on building your own home, you’re feeling confident in the plans you’ve made, and you can probably picture the finished home in your head. Now, it’s time to start making more big decisions, from the building system you’re going to use to the way you’re going to manage your project.

In this article, we’ll look at what you need to consider when it comes to the design and specification of your self build home.

Choosing a building system

It’s important that you choose the right building system for your project - there’s a variety of systems available and each one has its own benefits and drawbacks. Some are cheaper than others, some are more eco-friendly, and some help to accelerate build time. Let’s look at three of the most popular build systems on the market.

Timber frame

As the name suggests, a timber frame building system consists of timber beams and components that are put together to create a structure - or frame - of the home. One of the main advantages of timber frame is speed; many self builders use this system because it makes assembly quicker. Timber also has strong ‘green’ credentials - this is ideal if you’re planning or required to incorporate a certain level of sustainability into your new home, or if you’re simply keen for your self build project to be an environmentally friendly one.

Brick and block

Also known as modern or traditional masonry, brick and block is what most people think of when they picture a house building project. As this is such a popular, tried and tested method, you shouldn’t have any trouble finding a reputable builder with plenty of experience to build your home. It’s important that you take the time to research potential builders, though, as the overall quality of the finish will depend on just how skilled your builder is.

Structural insulated panels (SIPs)

Consisting of a foam core between two solid boards, SIPs are an efficient build system used in commercial and residential builds. The boards are usually Oriented Strand Board (OSB), and the panels themselves are strong and adept at achieving air-tightness. Typically, an SIP structure can be set up within five days.

These are the most popular systems for self build projects, but there are several others that can be used to build your dream home. Click here to read about the rest, from green oak to insulated concrete framework (ICF).

Designing your self build

Bringing an architect or designer on board not only helps bring your ideas to life, but it may also be necessary to achieve planning permission in some areas. Unless you’re a professional architect or designer yourself, contracting the services of a third party is highly recommended. As with all aspects of your self build project, it’s important to do your due diligence before pressing ahead with a designer or architect.

Finalising all your design ideas can seem quite daunting - you have to be absolutely certain of your choices before committing them to any sort of official plan. Here are a few things to think about when designing your self build.

The plot

Every plot of land has its own characteristics that can affect any house that’s built on it. Take care to study the unique features of the plot and figure out how your future home will work with them. Things like the orientation of your home will affect how much natural light it receives,

The suitability of your home will also play a role in whether or not your planning permission application is accepted; if your proposed home is likely to intrude on the privacy of existing homes, for example, this may affect the local planning authority’s decision.

The future

Your plans for the future are important. A growing family, or children flying the nest will change the way you use the home later down the line, for example. If you’re planning to live in this home for the rest of your life, consider how the layout will cater to any mobility requirements.

Drawing up detailed floor plans is the best way to convey your plans to the architect. These plans can ensure your home perfectly suits your day-to-day lifestyle, as well as accommodating for any potential changes in the future.

Do you need a professional architect or designer?

While hiring a professional designer or architect isn’t a make-or-break decision, we recommend doing it. Their experience and expertise can be invaluable to the project, and it can also be very helpful to have someone handle a portion of the workload to save you time and stress. Here’s what you need to consider when looking for a professional designer or architect for your self build project:


The services of a professional architect or designer will vary in cost, but they’re unlikely to be cheap. The right professional can certainly give you value for money, but make sure you can afford to shoulder the cost before entering into an agreement.


Make sure any architect you choose is registered with the Architects Registration Board (ARB). As the ARB states; “Anyone who describes themselves as an architect when designing or constructing buildings must be properly qualified, registered and insured [with the ARB]”. You can easily check if potential architects are ARB-registered by searching the register here.


Working with an architect or designer means exactly that; working together, so it’s important that you get on with the person you’re working with. Of course, their expertise will be invaluable and they’ll likely have plenty of input and ideas for your project, but ultimately, it’s a collaborative process, so make sure you feel comfortable working with them and sharing your ideas with them.

Equally, you’re paying them for their expertise, so make sure they bring theirs to the table. Above all, this is your project, so it’s important that you work with the right person to build the home you’ve envisioned.

Eco considerations

There benefits of building an eco-friendly home are manyfold. As well as being kinder to the environment, an energy-efficient home can help save you a significant amount of money on bills and running costs in the long-term. Furthermore, local planning authorities often look favourably on eco-focused homes, so consider this when planning yours.

As well as features like energy-efficient lighting and renewable energy sources, you can also use sustainable building materials, such as timber, for the actual construction of your home.

If you want to include sustainable features or materials in your home, make sure to discuss these with your architect or designer when planning your build so that they can be incorporated into the designs.

Click here to read about eco-friendly features for your new build.


Once the overall plans have been finalised and drawn up, you can start specifying the ‘second finish’ of your home, like bathrooms and kitchens. This is an exciting part of the process, but it’s important that you trick and stick to your budget - it can be easy to get carried away and see costs mount up as you choose more features for your home. Keep shopping around to find the best prices for your interiors and features to minimise the risk of going over your budget.

Your designer or architect should include the broader details of your kitchen and bathroom (or bathrooms) in their drawings - this for the benefit of those fitting things like pipework and electricity to and from those rooms. They may also recommend windows and doors that would meet thermal and planning requirements, but ultimately the finer details of the specification are up to you.

Planning conditions will also help to determine things like windows, roof tiles and external finishes in the early stages of the project, but you will be able to choose your lighting and flooring and other internal features later on. You’ll need to discuss these choices with your builder or contractors - they will likely have factored the installation of these features into their quote as a prime cost (PC), but be mindful that this is just an estimate and the actual cost may vary.

Internal specifications, such as heating, lighting, and floor finishes should be discussed with your builder at an early stage as decisions can impact other parts of the build.

For example, floor finishes will determine the exact dimension of your staircase. If you’re self-managing your project using sub-contractors, you’ll be expected to have an idea of what you want at an early stage and to make sure all of the affected trades are aware of what is required. The more information you can give, the more accurate your quotations will be.


Setting up electricity, gas and water will typically cost between £500-£10,000 - the final amount will depend on the specifics of your plot and what work needs to be done. If connecting your site to the utilities supplies means working across private land, you’ll need to secure a wayleave application to be authorised to dig. Similarly, you’ll need to be granted access to dig on public highways, if the situation calls for it. These factors can add time and money to the project.

Your architect or designer will factor in the location of utility connection points early on so that they can be connected at a later date. It’s important for them to do this so that certain connections - soil pipes and ‘hockey stick’ connections - can be built into the foundations. Space must be allowed for metre boxes and plants for heating the property, and their position is usually dictated by where services enter the building.

Contractors will need water and electricity during the build, but this does not mean that utilities have to be connected first. Generators or water bowsers can be brought onto site, or temporary supplies may be installed if electricity and water are already on-site. We advise organising all your utilities as soon as you take ownership of the plot of land, though; even though they’re not all vital straight away, it’ll be nice to have them set up and ready for when you do need them.

Don’t forget; you must have a plan in place for where you’ll stay during the build. Of course, if you still own your existing property, you can stay there while the build takes place, but otherwise you’ll need temporary accommodation.

Project managing a self build

Being your own project manager

Choosing to be your own project manager is a massive undertaking - if you already work full-time, you’re essentially giving yourself another job. While it will be hugely rewarding to be living in your finished home, the process can be long, stressful, hectic and unpredictable - as project manager, you’ll be the person who has to deal with the bulk of it. Make sure you’re fully prepared for project management and under no illusions as to the demands of the role before you commit to it.

Hiring a professional

A professional project manager brings a number of benefits. Firstly, their experience will be invaluable during the project, as they’ll know what to expect from the process and therefore be better equipped at navigating any obstacles that may arise.

They’ll also be able to shoulder most of the burden of the day-to-day aspects of the project - they’ll likely come to you for your input or to give you some of theirs, but ultimately you’ll be able to focus on your normal life while they handle the project.

All these benefits do come at a significant cost though. If you’re using a package home provider for your project, they may also undertake the project management role as part of your package, but this isn’t always the case. Paying for the skills, time and experience of a professional project manager can be a worthwhile cost, but make sure to factor it into your budget early on to avoid any unnecessary losses or financial gymnastics.

Finding tradespeople/contractors

As with every aspect of your self build project, from the materials to the plot, it’s vital that you take the time to find the right option for your needs. Choosing a project manager isn’t just a case of finding the cheapest or the most readily available - you project manager should fully understand what you’re trying to achieve and their skills should align with that.

It’s normal to interview project managers - you are giving them a job, after all. In an interview, you can see if you gel with them on a personal level, as well as judge their capabilities and track record. Ask for references and examples of past work, too; reputable project managers will have a strong portfolio of previous projects.

Make sure any potential project manager is a member of the Federation of Master Builders (FMB). When someone joins the FMB, they are independently inspected and professionally vetted to certify their integrity and quality. As the FMB website states, ‘professional builders join us to show the badge of quality to their customers’. If your project manager is a member of the FMB, you can have confidence that you’ll receive a certain level of service.

Questions to ask

First and foremost, make sure to get a full quote for the project. When asking for a quote, you should also ask about any anticipated additional costs - this can help you avoid any unwanted surprises further down the line. Whatever the quote is, you should establish a payment schedule - never pay the full amount up front. The project manager should also be able to give you an estimated completion date, provided you have given enough information about the project. You should get this in writing where possible.

Like any project, you can save money by handling some of it yourself. However, this can be time consuming and requires considerable skill and patience, so this should only be an option if you know you are prepared to take on any additional responsibilities and complete them to a high standard. Mistakes could push your project costs drastically upwards.

From the system to the project manager, every aspect of your project needs to be carefully selected if the process is to be as smooth as possible. With all the right people and parts in place, you can move forward with your self build dream.

Don’t forget, there are plenty of exhibits, shows and courses available where you can learn from house building experts - keep an eye on our What’s On page for more. For more information about self build design and specification, or to learn more about the other aspects of self building, please feel free to contact us today; we’ll be happy to help.

Our Building Systems Workshop is a free event that covers the pros and cons of each method of building, and offers expert tips and advice to help you decide which building system is right for your project.

For an in-depth overview of the full self build process, including designing your home, project management, and how to find the best tradespeople, our 3 day NSBRC Guide to Self Build Projects covers it all.

Before you Build your Home…Build your Knowledge with the NSBRC!

If you are contemplating building your dream home, or planning to improve your existing home, why not attend one of our NSBRC Training Courses first to build your knowledge and confidence?

Check out our range of in-person and virtual courses!