Getting planning permission approved is a major milestone—but for most homeowners, it’s only the beginning of the process.
Many projects stall after planning permission has been granted because people don’t realise there are still several legal and technical steps to complete before construction can begin.
This guide explains what typically happens after planning permission is approved and how to keep your project moving without unnecessary delays.
1. Check Your Planning Conditions
Most planning permissions are granted subject to conditions.
Some of these are pre-commencement conditions, meaning you cannot legally begin construction until they have been formally discharged by the local planning authority.
Typical conditions include:
- Approval of external materials.
- Detailed construction drawings.
- Drainage strategies.
- Landscaping.
- Cycle and refuse storage (particularly common in London boroughs such as Lambeth and Wandsworth).
Always read your decision notice carefully before making arrangements to start work.
2. Discharge Any Pre-Commencement Conditions
To satisfy planning conditions, you may need to submit:
- Additional drawings.
- Material specifications.
- Product information.
- Samples of external finishes.
Most local authorities aim to determine these applications within several weeks, although timescales can vary depending on workload.
3. Prepare Building Regulations Drawings
Receiving planning permission does not mean you are ready to build.
Planning drawings are intended to demonstrate the appearance and principle of the development. Builders require a much more detailed set of technical drawings that comply with the Building Regulations.
These typically include:
- Wall, roof and floor construction.
- Thermal insulation (Part L).
- Fire safety (Part B).
- Ventilation.
- Drainage.
- Structural details.
- Construction details used on site.
If you’re unsure about the difference, our guide Do I Need Planning Permission or Just Building Regulations Approval? explains when each type of approval is required.
4. Appoint a Structural Engineer
If your project involves:
- Removing load‑bearing walls.
- Steel beams (RSJs).
- Loft conversions.
- Roof alterations.
- Large openings.
you’ll normally require structural calculations and construction details prepared by a structural engineer.
These calculations form part of the Building Regulations submission and ensure the structure can safely support the proposed alterations.
Our article The Role of a Structural Engineer in Home Extension Design explains when structural calculations are required and why they’re important.
5. Consider the Party Wall Act
Planning permission does not override the Party Wall etc. Act 1996.
If your project involves:
- Excavating close to a neighbouring property.
- Cutting into a shared wall.
- Building on or near the boundary.
you may need to serve Party Wall Notices before work begins.
Ignoring the Party Wall Act can delay construction and lead to disputes with neighbours.
Our guide How the Party Wall Act Affects Loft Conversions and Home Extensions explains the process in more detail.
6. Check Whether You Need a Build Over Agreement
Many London properties have public sewers running beneath or close to the proposed extension.
If so, you may need a Build Over Agreement from the relevant water authority before construction starts.
This could involve:
- CCTV drainage surveys.
- Drainage protection details.
- Inspection chambers.
- Sewer diversion or relocation.
Our guide Build Over Agreements for Extensions explains when approval is required and what the process involves.
7. Appoint Building Control
Before construction begins, you’ll need to appoint either:
- Your local authority Building Control department, or
- A Registered Building Control Approver.
Building Control will inspect the work at key stages, including:
- Foundations.
- Drainage.
- Structural elements.
- Insulation.
- Final completion.
8. Obtain Accurate Builder Quotations
Once you have detailed Building Regulations drawings, builders can provide accurate quotations based on exactly the same information.
This helps to:
- Compare quotations fairly.
- Reduce unexpected costs.
- Minimise variations during construction.
- Improve cost certainty.
9. Start Construction
Before work begins, make sure you have:
- Discharged any pre‑commencement planning conditions.
- Completed your Building Regulations drawings.
- Obtained structural calculations where required.
- Resolved any Party Wall matters.
- Secured a Build Over Agreement if necessary.
- Appointed Building Control.
Taking these steps before construction starts can help avoid costly delays later.
10. Obtain Your Completion Certificate
When the project is finished, Building Control will carry out a final inspection.
If the work complies with the Building Regulations, you’ll receive a Completion Certificate.
This document is important because it demonstrates that the work was completed in accordance with the Building Regulations and is often required when:
- Selling your property.
- Remortgaging.
- Making insurance claims.
- Providing evidence of compliance.
Final Thoughts
Obtaining planning permission is an important milestone, but it is only one stage of the development process.
The projects that run most smoothly are those where homeowners plan ahead by dealing with planning conditions, technical design, Building Regulations, structural engineering and statutory approvals before work begins.
Taking the time to complete these steps properly can save significant time, money and stress during construction.
Need Help Moving Your Project Forward?
If you’ve recently received planning permission, our Building Regulations Drawings service explains how detailed technical drawings help projects move smoothly from planning approval to construction.
If you’re still deciding how to obtain Building Regulations approval, our guide Building Notice vs Full Plans: Which Building Regulations Application Is Best? explains the advantages and disadvantages of each route.
At Draw & Plan, we help homeowners across London with planning drawings, Building Regulations drawings, measured surveys and the discharge of planning conditions, providing comprehensive drawing packages to support every stage of the project.
Ready to take the next step? Contact us today for a free, no‑obligation quotation.
Disclaimer: This article is for general informational purposes only and does not constitute legal or professional advice. Always consult relevant professionals and local authorities before undertaking any development or change of use.