top of page
Technical Design

During this stage of the process the developed design has all of the relevant technical information added to allow the project to comply with Building Regulations and to provide a construction level of detail so that it can actually be built on site as it has been designed.  This stage is made up of 4 phases.


  1. Detailed Design & Building Control

  2. Specification & Schedule Of Works 

  3. Tender & Contract

  4. Contract Administration, Closeout & Handover

1.  Detailed Design & Building Control


Building Control compliance and build-ability is always considered from the very start of the design process but once the relevant approvals have been obtained this is the time to really consider:


  • what route you would prefer in terms of Building Control - Approved Inspector or Local Authority

  • what Consultants do we need to get involved at this stage

  • how the building will be constructed

  • how does the structure fit in to the design

  • how can we make the project come in within budget

  • what level of sustainability can we actually achieve


Below are a list of the main elements of this phase but there may be others depending on the complexity of your project.

Structural Engineering

At this point we would recommend engaging with the Structural Engineer formally.  They will provide you with a quote for their fees based on the complexity of the project and the structure required.  For a typical rear extension and loft conversion they will charge in the region of £2000-£2500 + VAT but this can vary.  They will invoice you directly for their fees.  Once we have a structural design we can then make sure this works with our proposed architectural design.  We find that 3D modelling is invaluable for this as we can easily see if a steel beam is too deep and will protrude below a ceiling or if new services such as pipework or ducting are clashing with the new steelwork. 

Party Wall

If you are building within 3m of a neighbour's structure and the depth of your new structure will be  at a lower depth you will require a Party Wall agreement or notice to be signed with your neighbour.  We will guide you through this process and align you with an independent Party Wall Surveyor.  This process can take 2-3 months so it is wise to engage as soon as possible.  The fees for this element will depend on the type of notice you need to serve and if your neighbours want to appoint their own Party Wall Surveyor or they are happy to use yours and you will be responsible their costs.


Build Over Agreement

 If you are building within 3m of a public sewer or a shared drain then you will need to apply to your water provider for a Build Over Agreement.  If this is required we can help guide you through the process.  This process can take up to two weeks to gain approval and cost approx. £343 plus any architectural fees for accompanying plans or details required.


Building Control

We always advise to engage with Building Control as early as possible, as there may be an element of the design that needs to be address in terms of fire safety that would have an impact on any proposed layout.  We work primarily with Approved Inspectors as we find that they are the most responsive, flexible and are quick to respond to queries.  Having built up a relationship with them over the years we also have a better understanding of the level of information that they require to approve the drawings.  For a typical rear extension and loft conversion they would charge approx. £2000 + VAT.  Once we have prepare technical drawings we would submit them for comment and approval.  Building Control will also check and approve the structural drawings and calculations.

Detailed Design & Building Control
Specification & Schedule of Works

2.  Specification & Schedule of Works


This phase deals primarily with specifying the exact construction materials and finishes that will allow the Contractors to price accurately, comprehensively and in such a way that it will be easier to compare prices like for like.  Things to consider will be:


  • what are my exact requirements as the client

  • what kind of heating system do I want

  • what type of floor and wall finish do I want

  • where do I want light fittings, switches and sockets

  • how much do I want to spend on my kitchen joinery and sanitary ware

  • how do I want to procure client items such as lighting, flooring, specialist equipment - do I want to purchase some of this directly or do I want the Contractor to handle everything

  • can I afford to move out and rent during the build or will I need to live in the property

  • do I have the time to manage the build myself or do I need to hire a Project Manager or Contract Administrator to administer a building contract, manage variations, contractor valuations, etc.


This is typically a 30-40 page document consisting of the preliminaries for the project and the detailed specification of all finishes, materials, systems, equipment, glazing, etc. that will make up the building.  To help guide you through this process we will send you a Specification Questionnaire to fill out which will hopefully provide us with all the information we need to get going.  This is what you and the Contractor will refer to during the build stage when discussing costs allowed for all of the aforementioned items.  Quantities are not mentioned here as they will be included in the Schedule of Works document.

Specification 1.PNG

Schedule of Works

This is a document that we provide that highlights exactly where items included in the specification are to be fitted and in what quantities.  The Contractor can use this document to price the works.  This is also critical to the success of a project, as if the SoW is comprehensive and accurate it will be difficult for either Contractor or Client disagree on what was included or excluded in the contract.  Without this SoW and specification it would be difficult to establish this with certainty and this can lead to arguments a hostile resentful build.

Tender & Contract

3.  Tender & Contract


Once we have prepared the detailed design drawings, Specification & Schedule of Work and obtained all other relevant Consultant information such as structural design, M&E design, H&S information, etc. we can then start compiling the tender package.  There are a few ways to tender your project but the traditional practice is to send tenders out to three of four Contractors.  


The tender package normally consists of the following information:

  • architectural drawings

  • specification & schedule of works

  • interior design information (if required)

  • landscape design & specification (if required)

  • structural drawings and calculations

  • m&e design specification and drawings (if required)

  • kitchen design (if available)

  • employer's requirements document

  • pre-construction information assessment

This is a non-exhaustive list and is subject to change depending on the scale and complexity of the project.  The tender process normally takes approx. 6-8 weeks with 4 weeks for pricing and 2-4 weeks to analyse the different tender prices and appoint a suitable Contractor.  On larger projects we may advise you to appoint a Quantity Surveyor.  They would advise on financial viability of the project from the very beginning but we will advise you if your project requires this level of scrutiny. 


We would always advise that Clients carry out their own due diligence when evaluating contractors i.e. checking their financial status and checking references. 



When you have appointed a Contractor, the next step is to agree if a contract will be put in place between Client and Contractor.  We would always advise employing a JCT Contract that both parties will sign.  This is in place to protect both parties in the event that there are any disputes over finances or quality of workmanship, the Client or Contractor go into liquidation, project delays, etc.  We can act as Contract Administrator for you in this case and we will advise you further when the time comes.  

When all the particulars of the contract have been agreed we will arrange a meeting where the contract will be signed and you are now ready to start on site!  


4.  Contract Administration & Handover


Once all contract documents have been signed and all legal requirements are in place the Contractor will begin to mobilise their materials, equipment and site staff to commence the project.  

Contract Administration

Most contracts will require some form of Contract Administrator to carry out the following duties:

  • Issuing instructions to the Contractor.

  • Issuing certificates under the building contract — for example payment certificates, practical or partial completion certificates and the final certificate.

  • Valuing the works and agreeing the final amount (where there is no quantity surveyor).

  • Dealing with contractors’ applications for extensions of time and extra payment.

  • Inspecting the works at stages during the construction and preparing defects lists at practical completion and at the end of the defects rectification period. This is not a duty to supervise the works unless the Contract Administrator is expressly appointed for this role and is aware of their additional responsibilities and duties.

  • Preparing the Health & Safety File and collating the Operation & Maintenance Manual for the project.

There are a lot of reasons why a project can go wrong or how the Client/Contractor relationship can deteriorate.  Appointing a Contract Administrator ensures that the best interests of the project itself is are at the core by monitoring the performance of both the Contractor and the Client, ensuring that the quality of workmanship is to a high standard, tracking cost variations, managing the budget, valuing the work on site and making sure that the particulars of the contract are being adhered to by all parties.  This allows for clear communication of ideas, issues and concerns throughout the project and a smoother process for all concerned.

Contract Administration & Handover


This phase of any project is the light at the end of the tunnel because it means the Contractor is preparing for the handover of the project to the Client.  This phase involves the following:


  • creation of a snagging list or a list of all of the unfinished works before the project is deemed to be practically complete.

  • preparation of the Health & Safety File by the Principal Designer.  This is a file containing information pertinent to the project highlighting any residual hazards or risks that any future Contractor would need to be aware of before carrying out their work.

  • preparation of the Operation & Maintenance Manuals (O&M's) by the Contractor.  This is a document that should include all of the relevant technical data sheets and specifications for any material, fitting, fixture or equipment that has been fitted or installed by the Contractor.  This ensures that appropriate maintenance and replacement can be carried out in the future.

  • agreeing the final account with the Contractor

  • monitoring the rectification period.  This is a period of 6-12 months after the project has been completed where any latent defects that have arisen in that time will need to be rectified by the Contractor before the final monies are released and the Final Certificate is issued.

bottom of page