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GUIDE TO THE PROCESS OF DESIGNING A NEW HOME OR EXTENSION


Are you thinking about designing a new home or extending an existing one?  This guide will describe the processes involved from conception to completion.  It is based on our experience as architects undertaking residential projects in and around Bath.  We have worked in a number of areas including Somerset, Gloucestershire, Wiltshire, Dorset and Devon, although the general processes outlined below will be similar throughout the country. You may also be interested in our companion design guides for new houses and house extensions.


BRIEF FOR YOUR NEW HOME OR EXTENSION

In the first instance we will help you consider what it is that you hope to achieve – how much space you will need, where you will need it, and for what purpose.  Perhaps you will have a grand vision of what you want to do.  Perhaps your aspirations are more straightforward or functional.  We will help you think about your brief and discuss options with you.  This may involve ideas that you have not considered or we may suggest practical / economic reasons why your original ideas might be best modified.  Our knowledge of the planning system will also inform what we consider might be achievable.

 

 

FEE PROPOSAL

Having discussed the brief and scope of work with you, we will prepare a fee proposal.  This will list each of the stages of work that you would like us to undertake and the fees associated with each stage.  Generally this will include a fixed fee for each component, based on the brief and scope of work set out in the proposal.  Our fees are never based on a percentage of the construction cost. The proposal will also set out an indicative program and identify any other consultants that we think will need to be involved.  Often, certain stages will be optional and you may decide to proceed with some of the services offered, but not others.  Work will usually commence within a few weeks of your written instruction to proceed. 

 

 

SURVEY & PREPARATION

Typically the first stage will involve creating a measured survey of the relevant areas of the existing house, adjacent buildings or external areas (as appropriate).  Drawings will include plans, sections and elevations.  These are used in a planning application to identify the existing condition.  They are also used for a builder to identify the starting point from which they will undertake work.


At this time we will also consider any constraints.  This may include for example existing services such as soil pipes and sewers, trees or topography.

 

Legal Issues

Understanding the site boundary will often be critical.  Sometimes your neighbours may disagree about the boundary line, which can have an impact on your proposals and delay the process.  We can guide you on this and advise if specialist legal input is required.  Your neighbours may have gained a Right to Light, which your proposed house, extension, garage or outbuilding could impinge upon.  Note that if a right exists, it would do so irrespective of whether planning permission is granted.  Again, we can advise you on any potential risks in this area.  Finally you should advise us of any Rights of Way or covenants that might impact on the proposals (these should have been identified by your conveyancer when you purchased the house or land). 



SKETCH SCHEME

This is where the vision starts to come alive!  We will work through your brief with the aim of finding the best possible solution.  We will present this to you, detailing the reasons behind our thought processes.  You will have the opportunity to make comments and we will adjust the design as required.  In some cases it may be appropriate to submit this initial material to the Planners to obtain pre-application advice.




PLANNING APPLICATION

Once the general principles of the design have been established, we will produce all the documents required for the Planning Application (or application for a Lawful Development Certificate).   This will include all the necessary drawings, forms, and any required reports.  Again, you will have the chance to discuss the proposals with us and make any comments before the material is submitted to the Local Authority.   It is also a good idea to speak to your neighbours about the proposals prior to submitting the application.


Design & Access Statement

For new houses and some extension projects, the application will need to include a Design and Access Statement.  This will explain the principles of design – what the proposal is and how it has come about – in the context of the existing physical environment.  It will also deal with how access issues have been considered.


Other Reports

Additional material will be required if the building is listed.  In certain cases, reports will need to be provided dealing with issues such as ecology, trees, highways or energy use.  Our Design Guide provides more information.


Submitting the Application

It usually takes a week or so for the application to be registered, then a further eight weeks for the application to be determined.  Small changes can often be made during this time in response to comments made on the application.  We have an exceptional record of achieving planning permission, based on our experience of balancing a desire to achieve our client’s goals, with what we consider will be acceptable to the Planners.

 

Planning Conditions

Often planning permission will be granted requiring further details to be approved  before building work can proceed.  This may for example include additional drawings of detailed elements (which we can provide) or a sample panel of walling / tiling (to be provided by the builder).

 

ADDITIONAL APPLICATIONS

Occasionally applications need to be made to other bodies.  Two common ones on residential projects include creating a dropped kerb (made to the Highways Authority) or building over or near a sewer (made to the Water Authority).  These may need to be accompanied by additional survey information.

 

 

HEALTH AND SAFETY

As your architect, we will have certain responsibilities for health and safety matters under the CDM Regulations.  As a client, you will also have responsibilities.  These vary depending on whether you are considered a domestic client or a commercial one.

 


BUILDING REGULATIONS APPLICATION

Following receipt of planning approval (or in some cases for extensions, a Lawful Development Certificate) it is normal to submit a Building Regulations application. Whilst a planning application deals with such matters as the use of a building, what it looks like, and the impact that it will have on others, a Building Regulations application deals with more technical issues.  It needs to consider:

  • The structure of the building

  • Fire safety

  • How the building keeps moisture and contaminants out and how it is ventilated

  • Prevention of toxic substances

  • Acoustic performance

  • Sanitation, water, drainage and waste

  • Combustion appliances

  • Protection from falling, collision and impact

  • Conservation of fuel and power

  • Access to and use of buildings

  • Electrical work including communications networks

  • Security


It is possible to submit a Building Regulations application in two ways: 

 

Building Notice

A Building Notice may be appropriate for small house extensions (when not building over or near a sewer) and loft conversions.  Here a simple form is submitted to the local authority and the contractor liaises with them on meeting the requirements of the regulations.  No drawings would be produced by us, but a structural engineer would be required to provide calculations / drawings for certain structural elements.  This route has the potential advantage of being quick and cost efficient, but the disadvantage that you will not know ahead of time whether the proposals will be approved.  You are relying on the builder’s judgement and experience.  It will also mean that the builder will price the works based on planning drawings, with only a limited amount of detail, and as such this will introduce cost uncertainty.

 

Full Plans

A Full Plans application will need to be made for a new house, and is often appropriate for extensions.  Here we will produce a set of detailed plans, sections and elevations with dimensions and annotation.  We will also produce a set of typical details – for example taking sections at ground level, window and eaves. For extensions, we will undertake a U-value calculation to determine the levels of insulation required for each element of the fabric – walls, floors, roof, windows and doors.  For new houses, we will engage an energy consultant to undertake a SAP calculation. We will also acquire a radon report to determine whether additional provisions are required at ground floor level.  We will liaise with the structural engineer to ensure that the design is properly coordinated. This package will be submitted to the local authority (or alternatively an approved inspector) for their approval.  This usually takes around 5-6 weeks. The majority of our clients take this route, as it has the advantage of providing more certainty on detail and costs.

 

Mechanical and Electrical Work

In our experience, it is not common for a mechanical and electrical engineer to be engaged on house extensions and modest new house projects.  Usually this aspect of the work is dealt with by what is termed ‘contractor’s design’ – where the builder’s plumber and electrician will be responsible for the design work and will issue a certificate of compliance.

 


PARTY WALL NOTICES

Where your extension, new house or outbuilding is within 3m (or 6m in certain cases) of a wall or structure on your neighbour’s property, it is likely that a Party Wall Notice will need to be served.  Note that a loft conversion invariably requires additional structural beams, which if resting on a party wall, will also trigger the requirement to serve a Party Wall Notice.  We can submit these notices on your behalf.  This is typically done once the structural engineer has produced their package for the Building Regulations application.

 

FURTHER WORK

Some clients will only engage us until this point and proceed with further stages themselves.  In such circumstances, we can recommend a user-friendly building contract that you can deploy.  We can also provide ad hoc advice or drawings on a time-charge basis.  By contrast, other clients will ask us to undertake additional work, as outlined below.

 

 

FITOUT DESIGN AND ADDITIONAL CONSTRUCTION INFORMATION 

The building regulations application only provides a limited amount of information and falls some way short of all the information required for a builder to fully price and complete the work.  We are able to provide the additional architectural information for you, which might include:

  • Kitchen, bathroom and utility room fitout design consisting of detailed plans and elevations for each room, with information on sanitaryware, cabinets, worktops, tiles, lighting, electrics and flooring

  • Joinery fitout design such as cloakrooms, shelving, walk-in wardrobes, and cupboards

  • Door and window schedules (including ironmongery)

  • Specification document covering architectural design areas that we will be dealing with

  • Schedule of finishes (walls, trim, ceilings and floors), fittings (cupboards, internal doors, sanitaryware), electrics (power and lighting) and plumbing (heating and sanitary supply / waste).  This takes the form of a list of items on a room-by-room basis.

  • Details of hard landscape such as paving, walls and steps

  • Electrical layouts for each room.  These show where the power sockets, light fittings and switches will be located.

 


TENDER PREPARATION & ANALYSIS

Initially we will prepare a pre-construction health and safety pack and discuss a suitable construction contract with you.  We will then assist you in compiling a list of typically three suitable builders, normally for a single-stage tender.  We will prepare a cover letter and draft contract, and submit to the potential builders with all the relevant documents produced to date.  Following this, we will attend a site meeting with the builders and respond to any questions they may have.  Finally we will assist you in evaluating the tenders, reaching an agreed contract sum, and signing the contract with the builder.

 

CONSTRUCTION STAGE

Administering the contract will mean ensuring that the work proceeds in accordance with the contract documents, to a reasonable quality, and according to a program that will enable the works to be completed on time.  This will typically entail undertaking site inspections every two or four weeks, where we will review progress.  We will also respond to the builder’s questions & make comments on their proposals.  We will check that they are billing an appropriate amount (typically each month) and issue a certificate identifying that the works are practically complete.  We will ensure that the contractor hands over the completed project with all instructions / manuals and that they undertake any required remedial work on defects after completion.

 

 

NEXT STEPS

We hope that you have found this guide useful.  If you would like us to help you realise your vision, please do get in touch.

 

 

DISCLAIMER. The information provided above is general in its nature and is based on our experience of previous projects.  It should not be considered to constitute professional advice for your particular project and should not be relied upon as such.

 

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