Extending your home is probably something that you’ll only do once in your lifetime. Ultimately, you want to make sure that you can build the size of extension that you want, within your budget.
Being aware of potential pitfalls and additional costs at the beginning of the process will help you make informed decisions.
I’ve put together a list of the top five things that are often overlooked when people carry out building work to their home – some of them have a significant cost implication, that may not have been budgeted for.
Forewarned is forearmed!
- The Party Wall Act 1996
- Construction (Design and Management) Regulations 2015 (CDM 2015)
- Planning Approval & Building Regulations Approval
- Building Over Agreement – Drainage
- Qualifications Of Designers
1. Party Wall Act 1996 (PWA)
What Does It Mean?
Put simply, if you are carrying out building work to your party wall or boundary and you damage it, you have a legal duty to repair it. In other words to act as a “good neighbour”.
It is a legal duty for a Building Owner to serve the appropriate notices in the correct manner. Failure to do so can result in an injunction being sought to stop the works.
For example, the Part Wall Act will apply if you carry out work to;
- Building a new party wall on the boundary or a wall adjacent to the building owner’s side of the boundary.
- Carrying out works to an existing party fence wall or party structure, including rebuilding a wall to a reduced height.
- Building within three or six metres of the adjoining owner’s walls or buildings if the works involve excavation works.
- Building or placing special foundations on the adjoining owner’s land.
Notice Requirements Under The PWA 1996
A building owner must give notice to all adjoining owners of any planned works. The notice requirements will depend on the type of works that are to be undertaken.
There are 3 types of notices;
- Line of Junction
- Party Structure and
- Notice of Adjacent Excavation
In many situations more than one type of notice is required and it is essential that you ensure all notices required under the Act are given.
When Should A Party Wall Notice Be Served?
Party Wall Notices should be served at the earliest opportunity in order to ensure that there is sufficient time for the notice to run and for negotiations, if a dispute arises, to be undertaken. However notices are only valid for 12 months so caution should be given so as not to serve the notice too early either as they may then expire before works commence. This is not usually an issue with smaller domestic scenarios but should be factored into larger, longer term projects.
Party Structure Notices are required to be served two calendar months prior to the commencement of works
Line of Junction and Notice of Adjacent Excavation one calendar month prior to the commencement of works.
Click here to read about your duties under the Party Wall Act
2. Construction (Design and Management) Regulations 2015 (CDM 2015).
What Are These Regulations?
The aim of the CDM regulations is to improve the Health, safety and welfare of workers in the construction industry.
Do These Regulations Apply To Homeowners As Well?
Yes. The regulations changed in April 2015 and now place a legal obligation on the homeowner (Client).
The homeowner is not expected to be an expert in construction, so you have the option to transfer your duties to the Contractor or Principal Contractor (If more than one contractor is working on the project).
Alternatively, the homeowner may choose to have a written agreement with a Principal Designer to carry out the duties.
What Are These New Regulations For?
They help ensure that no-one is harmed during the construction work, and that your building is safe to use and maintain while giving you good value. Effective planning will also help ensure that your work is well managed with fewer unexpected costs and problems.
Want to read more? Click here for more guidance
3. Planning Approval & Building Regulations Approval
With all building work, the owner of the property (or land) in question is ultimately responsible for complying with the relevant Planning rules and Building Regulations (regardless of the need to apply for planning permission and/or building regulations approval or not).
If you don’t follow these rules, as the homeowner you will be liable for any remedial action (which could go as far as demolition and/or restoration).
You will need to check that whoever you appoint to draw up your plans has suitable experience when dealing with the Local Authority – this will help smooth your path through the planning and building regulation process.
Planning Approval
You should receive a decision with within 8 weeks of registering your application. You need to make sure that you have included all of the relevant information and the correct fee, otherwise the clock doesn’t start ticking until the application is officially “registered”.
Factors Affecting Planning Permission
There are many factors that will affect whether or not you need to apply for planning permission or affect your chances of gaining planning approval.
Some properties have “permitted development rights”. This means that you can improve and extend your home without the need to seek a specific planning permission as long as you comply with a special set of rules.
Some properties do not have these rights, or may have had them removed. You will need to check with the Local Authority, who should be able to confirm this for you.
Permitted Development Rights
If your property has permitted development rights, there has been a temporary increase to the size limits for single-storey rear extensions, provided the construction work is completed by 30th May 2019. Before you make your Planning application, click here to see if your projects falls within these size limits.
Even if your building works do not require planning permission it would strongly advise you to apply for a “ Lawful Development Certificate”.
Lawful Development Certificate (LDC)
This is an application that you make to the Local Planning Authority – they will review your proposed building works – provided that it falls within permitted development parameters, they will issue you with a “Lawful Development Certificate”.
If you ever come to sell your property you will need this certificate to prove that any works carried out on your property are “lawful”.
This normally takes between 6-8 weeks for a decision.
For more information, about the factors affecting planning permission click here
For information about Lawful Development Certificates, click here
Building Regulations Approval
What Are Building Regulations?
The Building Regulations are minimum standards for design, construction and alterations to virtually every building. They are developed by the Government and approved by Parliament.
Building regulations set minimum standards for the design and construction of buildings to ensure the safety and health for people in or about those buildings. They also include requirements to ensure that fuel and power is conserved and facilities are provided for people, including those with disabilities, to access and move around inside buildings
What Do I Need To Do To Get Building Regulations Approval?
There are two methods of applying for Building Regulations approval; either a Full Plans application, or by a Building Notice application.
A “Full Plans” Application
It is a two-step process; approval of detailed drawings (Plans approval) and approval of on-site inspections (Inspections approval)
What Do You Need To Submit To Building Control?
Typically, you will need to submit detailed plans and elevation drawings and a detailed specification as to how the building will be constructed.
If you are carrying out structural work, then you will need to appoint a Structural Engineer who will produce the necessary details for the builder to build to and also the Structural Calculations to prove that the building will be structurally sound.
How Long Before I Get A Decision From Building Control?
The application is submitted for checking and a formal decision notice is given (normally within 8 weeks).
Advantages of using this method are;
- the plans can be examined and approved before work starts and
- the builder can work to the approved drawings in the knowledge that the detail complies with the regulations.
Approved plans may be used for up to three years after they have been approved, even if the regulations change.
A Building Notice Application is a less detailed form of application where minimal information is initially required and no formal decision is given.
You are relying on the builder to build without “approved plans”, generally Building Control do not like this type of application, as you are relying heavily on the competency of the builder on site.
If Building Control do not accept something the builder has done, you will be responsible for remedying it (making good). This often leads to an argument between the home owner and builder because neither party wants the additional costs.
Also, this form of application typically costs you more than a full plans submission as you have to pay all the costs upfront, rather than in two stages when you submit a Full Plans application.
If you have carried out building works to your property without obtaining Building Regulations approval you will need to apply for a Regularisation Certificate.
What Is A Regularisation Application?
“A regularisation application is a retrospective application relating to previously unauthorised works i.e. works carried out without Building Regulations consent, started on or after the 11 November 1985. The purpose of the process is to regularise the unauthorised works and obtain a certificate of regularisation”
As you have carried out work without prior approval the Local Authority may request that you “open up” the works so that they can ascertain if the building works comply with current standards.
As this is classed as an “enforcement application” it does not attract VAT, but the cost is greater than the other forms of application.
For more information, please click here
Pre-Application Inspections
Some Local Authorities offer a “pre-application” inspection service. This is where they will come out to site to look at your building to check it complies before you make a formal application.
Examples of this might be where you are proposing a two-storey extension, but need advice as to whether or not the existing foundations are able to take the extra load.
They would ask you to dig a “trial” pit next to the existing foundations, then Building Control would come out to inspect it. Often they would seek confirmation from your design Structural Engineer as well.
They charge a fee for this service, so best to check with your Local Authority.
4. Building Over Agreement – Drainage
A Building Over Agreement is an approval from your local water company for the building work that you plan to have carried out over, or near a public sewer owned by the local Water company.
What Is A Public Sewer?
A sewer is a pipe that serves more than one property. All drainage pipes (that connect to your local Water Authority) are now public sewers except where only one property is served by the existing pipe, which is known as a drain.
A drain is privately owned and maintained to the property boundary by the home owner, once it crosses the property boundary this pipe becomes the responsibility of the Water company.
Why Do I Need A Building Over Agreement?
If you are building over a public sewer, or one that runs within 3 metres of the proposed building works you have to make sure that the new foundations are far enough away from the drain and that sufficient access to the sewer is maintained so that they can clean or repair it if necessary. You will need to make sure that;
- The extra weight of the proposed building work near to or above the sewer could cause it to collapse, resulting in structural damage to the new building and
- the local water company have access to carry out maintenance and repairs.
Do I Always Need to Apply for A “Building Over A Sewer” Agreement?
You will not need a Building Over Agreement if you are able to move the building works so that they are more than 3 metres away from the sewer.
You may be required to divert the sewer. This work would be carried out by your local water authority, but at your cost.
How Do I Find Out If I Am Building Near A Public Sewer?
You will need to contact your local water authority and make an application either on line or by post.
How Much Does A Building Over Agreement Cost?
The cost depends on the size of the pipe. It can vary from £350 – £1,300.
What Do The Fees Cover?
- Processing the application
- Technical reviews of plans
- Discussing and agreeing any changes in design
- Liaising with the local authority in line with building regulations
- Issuing consent
- Registering the build over on records
- CCTV (Class II and BO Class III)
- Site visit to locate sewers if needed
What Is The Process Of Building Over A Sewer?
Make an application to the relevant water authority, enclosing the relevant site plans, sections and elevations of the proposed works. Include the correct fee.
You may need a CCTV survey before you begin work to see whether or not the pipe requires any repair work before the building work commences.
They might also carry out the CCTV survey after the building works to check to make sure that no damage has been done to the sewer.
How Long Does It Take To Receive Approval For Building Over A Sewer?
Approximately three weeks – you shouldn’t start any work on site until you have received approval.
5. Qualifications Of Designers
Your home is probably your largest asset. Therefore it is important that whoever you choose to help you with your design is professionally qualified.
There are many construction professionals who can help you. For example;
An Architect
The training and emphasis for an Architect is on design and philosophy of architecture.
An Architectural Technician
The training and emphasis for an Architectural Technician is on the science and technology of architecture
Whilst both disciplines have their own distinct training and specialism, there is considerable overlap between the two professions.
Chartered Structural Engineer
IStructE (Institution of Structural Engineers)
A Chartered Structural Engineer is someone who has demonstrated professional competence within the engineering profession. A Chartered Structural Engineer is a logical, practical person who is able to think around problems.
For more information about how you can “Build with confidence with a Structural Engineer” visit the Institution of Structural Engineers website
You might notice a familiar name on page 8! A 3D model showing some typical situations which would warrant the involvement of a Structural Engineer. Image produced by Michael Aubrey Partnership.
FindanEngineer.com is a comprehensive database of structural engineering practices across the UK that puts you in touch with the best structural engineer for any project. Only firms that have at least one member from the Institution of Structural Engineers can register.
Who Can Help Me With My Proposed Building Work?
As Structural Engineers, we work with Architects to develop schemes that will deliver projects that not only look amazing, but are buildable solutions, that are practical to build and are as cost effective as possible.
Do you have a project that you’d like expert advice on?
Either call us on 0118 962 9666 or click here to make contact with us and we’ll get back to you by the next working day (at the latest!).
Look forward to hearing from you.
What Is Structural Engineering?
Here’s a short video from the Institution of Structural Engineers
