Most people don't put off energy upgrades because they don't want a warmer home. They put them off because they're not sure what happens next. Who comes round? How long will it take? Is the house going to be a building site for a month? And who's meant to deal with the grant forms?
Fair questions, every one of them. So here's how a home energy improvement project actually runs with Greentek, from the first phone call to the day the paperwork lands in your hands. We'll also be clear about what you need to do at each stage, and what you don't.
Short Answer: There are five stages. You get in touch. We survey the house properly. We recommend what's worth doing and in what order. Our team does the work. Then we hand everything over and stay on hand afterwards. Grant applications, grid notifications and building regulations paperwork get dealt with for you along the way.
Key Facts at a Glance
- The Boiler Upgrade Scheme is run through your installer. You can't apply yourself, but Ofgem will contact you to confirm you're happy to go ahead.
- Once a voucher is issued, an air source heat pump has to be installed within 3 months.
- Since 21 July 2026, homes replacing oil or LPG heating can get £9,000 towards a heat pump instead of £7,500. That runs until 31 March 2027.
- England scrapped the rule that a heat pump had to sit 1 metre from your boundary in May 2025. Wales relaxed its own boundary rule in June 2026.
- Solar systems up to 3.68kW on a normal single-phase supply only need the local grid operator telling within 28 days of switch-on. Bigger systems need approval first.
Step 1: What Happens When You Get in Touch?
We have a chat about what's bothering you and work out whether a visit makes sense. Most people ring about one thing, say a heat pump or solar panels. But the conversation is really about the whole house, because that's what decides whether the thing you've asked about will work.
Expect a few questions. What kind of house is it, and roughly when was it built? How do you heat it now? What's going wrong: cold rooms, big bills, damp? Is any building work coming up? None of it is a test. It just means the visit is more useful when it happens.
What Helps to Have Ready
- A recent energy bill, ideally one showing your usage in kWh.
- Your Energy Performance Certificate (EPC), if you have one. It's on the public government register, so it can be looked up if not.
- A rough list of the rooms that feel cold or damp.
- Photos of the boiler, the meter and the loft, if you're happy to send them. They help, but they're not essential.
- Any plans for an extension, a loft conversion or a new kitchen.
Is There a Charge for the Consultation?
No. The first consultation and the quote are free.
What If You Only Want One Thing Done?
That's absolutely fine. If you just want solar panels, we'll quote for solar panels. We'll still glance at the rest of the house, mind, because sometimes it changes the answer. A heat pump quote means very little if the loft has 50mm of insulation in it. But we'll only suggest extra work if it genuinely affects the job you asked about, and you're free to say no.
Step 2: What Happens During a Home Energy Survey?
We look at the whole house, inside and out, and at how you live in it. The home energy survey is the most important stage of the lot, because everything we recommend comes out of it. A rushed survey leads to a guessed quote.
Every house is different, so no two surveys are quite the same. Here's what we're usually looking at, and why.
| What we check | What we're looking for | Why it matters |
|---|---|---|
| Walls, inside and out | Cavity or solid, any existing insulation, damp, the state of the brick or render | Decides which wall insulation, if any, suits the house |
| Loft and roof | Insulation depth, airflow at the eaves, roof condition, which way it faces, shading | Loft top-up, and whether solar panels make sense |
| Heating system | Boiler age and type, radiators, pipework, controls, hot water | Whether to upgrade the boiler or controls, or move to a heat pump |
| Rooms and windows | Room sizes, window types, draughts | Feeds straight into the heat loss calculation |
| Ventilation | Extractor fans, trickle vents, air bricks, signs of condensation | Makes sure new insulation won't lead to damp |
| Electrics | Meter, fuse board and supply | Needed for solar, batteries and heat pumps |
| Outside space | Where a heat pump unit could sit, access for scaffolding | Noise and planning checks, and practical installation |
Why the Heat Loss Calculation Matters
If a heat pump or new radiators are on the cards, we work out a room-by-room heat loss calculation. In plain terms, it tells us how much heat each room loses on a cold winter's day. That figure decides how big the heat pump needs to be and how big each radiator should be. MCS standards require it for heat pump installations, and honestly, it's the single biggest factor in whether a heat pump ends up cheap to run or not.
Step 3: How Do We Decide What to Recommend?
We recommend what will make the biggest difference to your house, in the order it ought to be done. Sometimes that's a heat pump. Sometimes it's loft insulation and better controls first, and the heat pump can wait a year.
The order matters more than people expect. A heating system is sized to match the heat a house loses, so if the house is leaking heat, you'd end up paying for a bigger system than you need. That's why we usually start with insulation before talking about new heating.
When We'll Tell You Not to Go Ahead
Sometimes the honest answer is "not yet" or "not this". A roof that's near the end of its life should really be sorted before solar panels go on it, or you'll be paying to take them off again. A cavity wall that faces driving rain, or one full of old rubble, may not suit cavity insulation at all. And a heat pump in a very draughty house can end up costing more to run than the old boiler. If the survey turns up something like that, we'll tell you, even if it means a smaller job for us.
What Your Quote Should Spell Out
- Exactly what's being installed, with makes, models and sizes.
- The design behind it, such as the heat loss figures and system size.
- Any grants taken off the price, and what you'll pay after them.
- What's included, like scaffolding, making good afterwards and building regulations sign-off.
- Rough timescales and how the payments are split.
- What's covered by warranties and guarantees, and for how long
Grants and Finance
For heat pumps, the Boiler Upgrade Scheme takes £7,500 off the price in England and Wales, or £9,000 if you're replacing oil or LPG heating until 31 March 2027. On top of that, installing energy-saving materials like insulation, heat pumps and solar panels in your home comes with 0% VAT until 31 March 2027.
If you'd rather spread the cost, we also offer finance options through our finance partners. We'll go through what's available with you when we send the quote
There's No Rush to Decide
Take your time with the quote. Ask questions, and compare it with others if you like. We'd honestly rather you did. Our guide on what to look for when comparing installers is a good place to start.
Step 4: How Is the Work Planned and Carried Out?
Paperwork first, then dates, then the work itself. We sort out the approvals and notifications before anyone turns up with tools, agree a start date with you, and keep you posted as the job goes along.
What Can Affect the Start Date
A few things sit outside anyone's control, so it's worth knowing about them up front:
- Grant vouchers. For a heat pump, the grant voucher has to be issued before installation. You'll need to reply to Ofgem's email promptly too.
- Grid approval. Larger solar or battery systems need the local grid operator's approval first, which can take weeks.
- Planning. If a planning application is needed, the council normally has up to eight weeks to decide.
- Weather. Rendering and roof work don't mix with heavy rain or frost, so outside jobs sometimes move by a few days.
- Surprises in older houses. Rotten timbers or old wiring occasionally turn up once work starts.
The Paperwork We Handle
| Paperwork | When it happens | Who does it |
|---|---|---|
| Heat pump grant voucher | Before installation (it can't be claimed afterwards) | We apply. Ofgem then contacts you to confirm |
| Solar grid notification (G98, systems up to 3.68kW) | Within 28 days of switch-on | We do |
| Solar grid approval (G99, larger systems) | Before installation, and it can take up to 45 working days | We do |
| Planning checks | Before installation | We check; an application is only made if one's needed |
| Building control sign-off | After the work is finished | We do, through a competent person scheme or building control |
| MCS certificate | After commissioning | We do |
Most air source heat pumps in England are now permitted development, which means no planning application, as long as the unit passes a noise check. Listed buildings, conservation areas and flats play by different rules, so we'll flag it if that applies to you. Outside wall insulation can need planning permission in some areas too, and that's something we check before quoting for external wall insulation and rendering.
How Long Does Installation Take?
It really depends on the job and the house, and your quote will give you proper dates. As a rough guide, though:
- Loft insulation is often done in a day.
- A solar PV installation usually takes a day or two once the scaffolding is up.
- An air source heat pump installation typically takes a few days, longer if radiators or pipework are being changed.
- External wall insulation takes longer, often a couple of weeks or more, depending on the size of the house and the weather.
What It's Like Having the Work Done
There'll be some disruption. We won't pretend otherwise. Depending on the job, the heating or power may need to go off for a while, and there may be scaffolding up for a bit. We'll tell you in advance what to expect each day, protect floors and furniture where we're working, and tidy up as we go. If something unexpected crops up, which can happen with older houses, you'll hear about it from us straight away rather than on the final invoice.
Step 5: What Happens After the Work Is Finished?
We test everything, show you how to use it, hand over the paperwork and stay on hand afterwards. A job isn't really finished until you're comfortable with the new system
Handover and Paperwork
Depending on the job, you should get:
- Your MCS certificate, for heat pumps, solar panels and batteries.
- Building regulations compliance and electrical installation certificates.
- Warranty and guarantee documents.
- Product manuals and commissioning records.
Keep them all together somewhere safe. You'll need several of them if you ever sell the house.
Getting Used to a New System
Heat pumps in particular take a little getting used to. They work best running steadily at lower temperatures, rather than blasting on and off like a gas boiler, so radiators feel warm instead of hot. We'll walk you through the controls, and it's worth giving it a few weeks to settle in.
With solar panels, you'll usually get a monitoring app showing what the system is producing. To get paid for the electricity you send back to the grid, you'll need to sign up for the Smart Export Guarantee with an energy supplier, using your MCS certificate. We'll explain how to register for the Smart Export Guarantee step by step soon.
Aftercare
Most heat pump manufacturers ask for an annual service to keep the warranty valid, so it's worth booking that in. And if anything doesn't seem right in the first few weeks, ring us. That's what aftercare is for.
What Do You Need to Do as the Homeowner?
Not a lot, honestly. But a few things do need you rather than us.
- Be there for the survey. We need to get into the loft, the airing cupboard and round the outside, and talking to you is half the point
- Read the quote properly. Ask about anything that isn't clear before you sign.
- Reply to Ofgem's email. If you're getting a heat pump grant, Ofgem will ask you to confirm. The voucher can't be issued until you do.
- Clear the way on the day. Empty the airing cupboard, make space in the loft, and move the car if scaffolding's going up.
- Sort out your finance in good time. If you're using finance, get it agreed before the start date.
- Register for export payments. With solar, sign up for the Smart Export Guarantee once you have your MCS certificate.
- Keep the paperwork safe. You'll want it for warranties, servicing and selling the house one day.
Getting Expert Help in the West Midlands and Wales
A good home energy improvement project shouldn't feel like a mystery. You should know who's coming, what they're checking, what they recommend and why, and what happens after they've gone. That's the whole idea behind the way we work.
Greentek Energy Ltd is one accredited team for building work and energy upgrades, from insulation and rendering to heat pumps, solar PV, battery storage and full renovations. Our office is at Birmingham Business Park in Solihull, and we work with homeowners across the West Midlands and Wales, including Coventry, Birmingham, Wolverhampton, Dudley, Cardiff and Swansea. Ring us on 0333 533 4567 or book a free consultation to get started.
