Resi vs Suddeco: A Factual Comparison for UK Home Renovation

Two prominent options for UK home extensions are Resi — an established architectural design practice — and Suddeco — an AI-powered platform that generates instant renders, concept drawings, and priced designs based on local planning precedents. Both help homeowners move from idea to approved project, but they operate on fundamentally different models.

This page provides a factual, side-by-side comparison on measurable features only: speed, pricing, service scope, and outcomes. No marketing spin. If you are considering either service for a kitchen extension, loft conversion, or rear extension, this guide will help you decide which model fits your needs.

Side-by-Side Feature Comparison

Key distinction: Resi operates as a traditional architectural design practice with a digital workflow. Suddeco combines AI-driven precedent analysis with human architect oversight to compress the early design phase from weeks to days. Resi suits homeowners who prefer a conventional architect-led process; Suddeco suits those who want rapid visualisation and data-backed design choices based on what has already been approved near their property.

Pricing Comparison

Resi (Typical Pricing Structure)

Total typical cost for a £75,000 extension: £4,000–£12,000+ in design and planning fees, plus 10–15% of construction cost if project management is added.

Suddeco (Fixed-Price Packages)

Total typical cost for a £75,000 extension: £2,495 for design and planning, plus a fee + percentage of build cost if Design-to-Build is selected. The Design+Planning package is typically 40–60% less than traditional architect-led planning costs.

Cost transparency: Resi pricing is quote-based and varies by project size and location. Suddeco publishes fixed prices upfront. The free render provides an immediate cost estimate based on your address and local build rates, with no obligation to proceed.

When to Choose Resi

Resi may be the better fit if you:

• Prefer a traditional architect-led relationship with extended consultation time
• Have a highly complex project (e.g., new build, Grade II listed property, extensive structural alterations)
• Are comfortable with a 2–4 week timeline for initial concepts
• Value an established brand with a long track record in the UK market
• Have a flexible budget and are prepared for quote-based pricing

When to Choose Suddeco

Suddeco may be the better fit if you:

• Want to see what your extension could look like within minutes, not weeks
• Want your design informed by real local planning approvals — what actually got permitted on your street
• Prefer fixed, transparent pricing with no hidden fees
• Want unlimited revisions included in the planning package
• Value milestone payment protection and a 12-month warranty on build projects
• Want to compress the design-to-planning timeline from months to weeks
• Are planning a standard extension type (rear, side return, loft, kitchen, wrap-around)

What Your Build Will Actually Cost

Regardless of which design service you choose, construction cost is the largest component. According to data from the Federation of Master Builders, the HomeOwners Alliance, and Checkatrade, UK construction costs in 2026 average £1,800–£2,800/m² for a single-storey extension, with a +30–50% premium in London and a -10–20% discount in the North and Scotland.

Additional fixed costs: planning permission (£206–£462), building regulations (£200–£1,000), party wall (£700–£2,000), structural engineer (£500–£2,000), architect/design fees (5–10% of build cost or £2,495 fixed with Suddeco), and contingency (10–15%). A typical 20 m² single-storey rear extension in the Midlands costs approximately £41,800–£71,500 all-in. For a detailed breakdown, see our extension cost guide or pricing page.

Frequently Asked Questions

Is Suddeco an architect or a tech platform?

Suddeco is an AI-powered design platform with human architect oversight. Our technology generates instant renders and analyses local planning precedents; qualified architects review and refine all designs before submission.

Does Resi offer a free render like Suddeco?

Resi does not currently offer an address-based instant render. Their process typically begins with a paid consultation. Suddeco's free render is available immediately by entering your UK address — no payment required.

Which service is faster for getting planning permission?

Suddeco's Design+Planning package delivers concepts in 48 hours and full planning submission in 5–7 days. Resi typically takes 2–4 weeks for initial concepts. Both services handle the full planning application process.

Are Suddeco's planning success rates better than Resi's?

Suddeco's AI analyses nearby approved applications to design within local planning norms. Resi has a strong track record through experienced architect preparation. We do not have access to Resi's internal statistics, so we cannot compare directly. Both services offer professional planning support.

Can Resi or Suddeco handle complex projects like listed buildings?

Resi has experience with complex and heritage projects. Suddeco is optimised for standard householder extensions. For Grade II listed properties, consult both providers directly.

What is the difference in total cost?

For a typical £75,000 extension, Resi's design and planning fees typically range from £4,000–£12,000+, plus 10–15% of build cost for project management. Suddeco's Design+Planning package is £2,495 fixed, with Design-to-Build adding a fee + percentage of build cost.

Does either service include building regulations drawings?

Yes. Resi includes them in premium tiers. Suddeco includes them in the £2,495 Design+Planning package at no extra cost.

Can I use my own builder with Suddeco or Resi?

With Resi, you can use your own builder or their partner network. With Suddeco, you can use your own builder with Design+Planning, or choose from our vetted builder network with Design-to-Build.

What happens if my planning application is rejected?

Both services support resubmission or appeals. Suddeco includes unlimited revisions in Design+Planning and uses local precedent data to reduce rejection risk. Resi handles appeals according to their service terms.

Is there a warranty on the build work?

Suddeco's Design-to-Build package includes a 12-month warranty. Resi's warranty terms depend on the individual builder used. Always confirm warranty details before committing to construction.

Which is better for a first-time renovator?

Suddeco is often preferred by first-time renovators because the free render provides immediate visual feedback, fixed pricing removes uncertainty, and the platform guides you through each step. Resi suits those who want a traditional, consultative architect experience.

Do both services cover the whole UK?

Yes. Both Resi and Suddeco operate nationwide across England, Scotland, Wales, and Northern Ireland, though planning rules vary by local authority.

Get Your Free Render Today

The fastest way to compare is to see it for yourself. Enter your address and get an instant render, plans, and cost estimate — completely free. No obligation. No credit card required.

Start Your Free Render →

Alternatively, explore our fixed-price packages or read our complete extension cost guide to plan your budget with confidence.