These are two entirely separate approvals, covered by different legislation. Planning permission deals with the appearance of a proposal and its effect on neighbouring properties and the wider environment. Building regulations deal with technical and constructional details — ensuring the health and safety of people in and around the building. In most cases, a proposed development requires both, meaning two separate applications and two separate fees. Your designer will advise which applies and can manage both processes on your behalf.
The statutory target for a householder application — extensions, loft conversions and the like — is eight weeks from validation. In practice, timelines are often longer. Local planning departments across England are under significant strain, facing staff shortages and rising workloads. Building in time for drawings and a site survey before submission, a realistic end-to-end timeline from first meeting to planning decision is typically four to six months for a straightforward residential project.
The planning application fee is set nationally and paid directly to your local authority — it’s separate from your designer’s fees. Householder applications increased from £258 to £528 from 1 April 2025. On top of that, there’s a Planning Portal service charge of £70 (inc. VAT) for online submissions. Fees will increase annually on 1 April each year in line with CPI inflation, capped at 10%. Your designer’s fees for preparing and managing the submission are charged separately — always confirm what’s included in your quote.
There’s no guarantee, but well-prepared applications for straightforward residential work have a strong track record. Around 90–95% of planning applications are decided by planning officers under delegated powers, based on planning merits. Choosing a designer with strong knowledge of your local authority’s policies — and direct experience submitting in your area — significantly improves your chances. Retsof Design has been submitting applications in the Wycombe area since 2015 and has a track record of first-time approvals.
Yes, for most projects. Before design work can begin properly, a measured survey of the existing property is needed to produce accurate drawings — including the location of utility services such as water, drainage, gas and electrical supplies. At Retsof Design, the site survey is carried out by the team directly and typically takes two to four hours depending on the size and complexity of the property.
Yes, but these are two distinct sets of drawings produced at different stages. Planning drawings show the proposed design in enough detail for the local authority to assess it. Building regulations drawings — sometimes called technical or construction drawings — are far more detailed, covering structural, fire safety, insulation and drainage information so the build can be properly inspected and signed off. They are usually quoted and invoiced separately.
That’s up to you. At a good firm, your brief drives the design from day one. Retsof Design’s process includes multiple review stages: first draft drawings, an on-site meeting to discuss changes, and a period of reflection before anything is finalised. Whether you want to be hands-on throughout or prefer a more turnkey approach, the key is finding a designer who can work to your preference. Always ask to see a portfolio at the first meeting and trust your instincts.
A refusal isn’t necessarily the end of the road. If an application is heading for refusal, the planning officer will often offer the chance to withdraw it — however it’s frequently better to receive the refusal, as it then opens the right to appeal. If an application is refused or withdrawn, you can reapply at no additional fee to the local authority. An experienced designer will review the reason for refusal, advise whether amendments could resolve it, and guide you on whether to reapply or appeal.
Local knowledge genuinely matters in planning — what one authority considers acceptable can differ significantly from one district to the next. Retsof Design is based in Naphill, High Wycombe, and has been working across Buckinghamshire since 2015. Familiarity with the Chilterns Area of Outstanding Natural Beauty, local conservation areas, and Buckinghamshire Council’s planning policies is built into everything they do.
Fees can be structured as a percentage of build cost, giving some flexibility if the project scope changes, or as a fixed fee, offering clearer budgeting upfront. If the scope changes or additional work is requested after costs have been agreed, you can expect additional fees. A good question to ask at every stage is: “How will this change affect what you charge me?” Always get a clear written quote before work begins and confirm what’s included at each stage.
Not all architectural design firms do — so it’s worth checking. Retsof Design offers both architectural and interior design services. Beth and James work together across projects to ensure continuity from the first sketch through to the finished space. This is particularly valuable for loft conversions, extensions and open-plan reconfigurations, where interior layout and structural design are closely linked.
Most reputable firms offer a free initial consultation, and Retsof Design does. To make the most of it, bring any photos, sketches or inspiration images you’ve gathered, a rough sense of your budget, and a list of your must-haves and deal-breakers. The clearer your vision at the outset, the smoother the process from that point forward. You can book directly at retsofdesign.com.
