Most people wait 4–8 weeks. Some wait 16. Why? Because they don’t understand how approval timelines actually work.
Here’s what nobody tells you: approval speed depends less on the scheme and more on when you apply, how you apply, and whether your installer knows the shortcuts. With ECO4 ending in March 2026 and new schemes launching with no track record, timing matters more than ever.
Let’s break down exactly how fast each scheme approves grants—and what you can do to speed things up. Understanding Central Heating Grants and the process can help ensure you get your upgrades sooner rather than later.
The Reality: Approval Times by Scheme
Want the truth? Here it is.
| Scheme | Average Approval | Fastest Possible | Common Delays |
| ECO4 | 6–8 weeks | 3 weeks | Supplier backlogs, survey scheduling |
| Boiler Upgrade Scheme | 4–6 weeks | 2 weeks | MCS installer availability |
| Warm Homes Plan | 8–12 weeks | 5 weeks | Council capacity, regional rollout |
Notice something? The “average” means half the applications take longer. If you’re applying in winter when demand peaks, add 2–4 weeks to everything above.
Why ECO4 Approval Takes Longer Than It Should
ECO4 ends March 31, 2026. That deadline creates two problems. First, suppliers are rushing to clear their obligation targets, which floods the system with late applications. Second, installers are prioritising jobs they know they can complete before the cutoff—meaning new applications sit in queues longer.
The approval process breaks into four stages: eligibility check (3–5 days), technical survey (1–3 weeks wait time), measure design (5–7 days), and funding approval (7–10 days). Total? Six weeks minimum if nothing goes wrong. But things go wrong constantly, missing documents, survey rescheduling, and measure changes after inspection.
The Boiler Upgrade Scheme Moves Faster—Here’s Why
BUS approves faster because it’s installer-led, not supplier-managed. Your MCS-certified installer submits your application directly to Ofgem. No energy supplier middleman. No obligation targets create artificial bottlenecks. The system processes applications in 2–6 weeks, with most falling around 4 weeks.
The catch? MCS installer availability. High-demand areas see 4–8 week waits just to book an initial survey. So your “4-week approval” becomes 8–12 weeks total from first contact to funded installation date.
Want to move faster? Contact three installers simultaneously. Book with whoever can survey soonest.
Warm Homes Plan: The Unknown Variable
The Warm Homes Plan launched in spring 2025. Nobody has solid data yet on consistent approval timelines because rollout remains patchy across councils.
Some councils approve in 5 weeks. Others take 14. The difference? Internal capacity and whether they’ve partnered with established ECO4 delivery companies or built new procurement frameworks from scratch.
What Actually Slows Down Your Approval
Incomplete eligibility documentation. You think you’ve submitted everything. You haven’t. Missing benefit letters, outdated EPCs, unclear proof of ownership—these add 1–2 weeks while providers chase you for corrections.
Survey scheduling conflicts. Surveyors book 2–3 weeks out during peak seasons. Miss your slot? Back of the queue. Another 2–3 weeks gone.
Measure compatibility issues. Your home’s survey reveals problems—inadequate insulation for a heat pump, structural issues preventing wall upgrades. Now you’re negotiating alternative measures, resubmitting plans, waiting for secondary approvals. Add 3–4 weeks.
How to Get Approved Faster Than Average
You’re not helpless here. Smart applicants cut weeks off these timelines.
Apply Early in the Quarter
Suppliers and councils process applications in waves. Apply January–March? You’re competing with everyone rushing before deadlines. Apply April–June? You’re in the priority queue because providers need to maintain steady installation pipelines.
Exception: ECO4 in early 2026 will be chaos. If you’re considering ECO4, you need to apply in December 2025. Now? Switch to the BUS or Warm Homes Plan instead.
Submit Perfect Documentation First Time
Here’s your checklist. Get these ready before starting any application:
- Current EPC (dated within 10 years, showing D–G rating for Warm Homes Plan)
- Proof of benefits (official letters, not screenshots)
- Property ownership documents (title deed or mortgage statement)
- Current energy bills (last 3 months)
- Photo ID and proof of address
One submission. Zero follow-ups. You just saved 10–14 days.
Choose Your Installer Strategically
Not all installers are equal. Some have dedicated admin teams handling applications while technicians focus on installations. Others have one-person operations where the surveyor is also processing your paperwork.
Ask potential installers: “What’s your current approval timeline from survey to funded installation?” If they can’t answer specifically, they don’t have systems in place. Find someone who can.
Use Multiple Scheme Applications
Nothing stops you from applying to BUS and Warm Homes Plan simultaneously. Different schemes, different administrators, zero conflict.
Apply to both. Accept whichever approves first. Withdraw from the other. Yes, this creates administrative work for providers. No, you shouldn’t care—your heating system matters more than their convenience.
The March 2026 Deadline Changes Everything
ECO4 officially ends March 31, 2026. That’s not a “subject to extension” date—the government confirmed no continuation in November 2025.
What does this mean for approval timelines? Chaos.
Installers are triaging applications now. If they can’t guarantee completion by March 31, they’re rejecting new ECO4 work entirely. So “6-week approval” becomes “application declined” for anyone applying after mid-January 2026.
Your Real Options After ECO4
Post-April 2026, you have two funded pathways: BUS for heat pumps (running until December 2027) and Warm Homes Plan for low-income households (timeline uncertain, but confirmed through at least 2026).
BUS approval times will likely improve after April because MCS installers will have excess capacity when ECO4 work disappears. Expect timelines to drop from 4–6 weeks to 3–4 weeks by summer 2026.
What Happens If You’re Already Waiting
Contact your provider immediately. Don’t wait politely. Call weekly. Reference your application number. Ask specific questions: “Has my eligibility been confirmed?” “When is my survey scheduled?” “What’s the current processing stage?”
Escalate if necessary. ECO4 providers have complaint procedures. Use them. Warm Homes applicants can contact their council’s energy team directly. BUS applicants can switch installers mid-process if the first one goes silent.
The Bottom Line
Here’s what matters: ECO4 is effectively closed for new applications. BUS approves in 4–6 weeks if you choose the right installer. The Warm Homes Plan takes 8–12 weeks, with significant regional variation.
Want faster approval? Submit flawless documentation, apply to multiple schemes at once, and select installers with proven processing speed—not just the cheapest quote or the largest company.
The difference between a 4-week approval and a 12-week approval often comes down to preparation. Many people wait longer because they’re sloppy with paperwork or passive with follow-up. When planning your heating upgrades, it’s also useful to know do radiator covers stop heat to ensure maximum efficiency and comfort.
