Crisp lines. Premium feel. Built to last.
Aluminium entrance doors give you a modern look with strong, slim profiles and a reassuring, solid close. Powder-coated finishes stay smart, hardware feels engineered, and thermal breaks keep the hallway warm.
We survey, supply and fit across Grantham, Stamford, Sleaford, Newark, Bourne, Melton Mowbray and nearby villages.
Modern, architectural look
Flush panels, sharp sightlines and designer hardware that lifts the whole frontage.
Premium feel
Stiff, stable slabs and frames with a confident latch and quiet close.
Strong and secure
Multi-point locking, robust hinges and quality cylinders as standard.
Warm hallway
Thermally broken profiles and high-performance glazing help reduce draughts.
Low maintenance
Durable powder coat. No peeling paint — just a simple wipe clean.
• Flush contemporary: smooth skins with clean detailing. • Grooved/linear: subtle channels for texture and depth. • Glazed accents: slim vertical or square lights for daylight without losing privacy.
• Side panels (one or both sides) to widen the look and add light. • Top lights over the door for extra height and brightness. • Equal sightlines so door and side panels read as a single system.
• Popular tones: anthracite, black, white, warm neutrals. • Heritage options: softer greys and greens. • Dual colour available on many systems (e.g., dark outside, white inside). • Matt, satin or textured powder coats.
• Pull bars, lever handles or knob sets in stainless, black, chrome or brass tones. • Letterplates, viewers and knockers to match. • Colour-matched hinges and thresholds where the system allows.
• Standard weathered threshold for maximum sealing. • Low threshold options for easier access — we’ll explain weather performance so you can choose confidently.
Thermally broken aluminium plus low-e glazing in any side lights helps keep warmth in and cold out. You’ll notice fewer draughts on the stairs and landing.
Multi-point locking around the frame, reinforced keeps and quality cylinders. Laminated glass for side panels and larger glazed sections where required.
Tight seals and laminated glass options help cut road noise on busier streets.
Rigid frames that don’t warp, with finishes designed for years of everyday use.
We visit, measure properly, look at your existing frames and talk through finishes, glazing and hardware. It’s a conversation, not a sales pitch.
You’ll get an itemised quote with the style, colour, glass spec, lead time and warranty. No vague “from…” pricing and no surprises later.
Every frame is built for your apertures. This is what keeps the installation neat and the seals tight.
We protect floors, remove old frames and glass, seal up neatly and clean down. Old materials are taken away. You’re not left with a skip.
If you ever need us, you don’t get pushed to a call centre. You speak to the same team who fitted the job.
We measure properly, check clearances and talk through panels, glazing, colours and hardware. It’s a conversation, not a pitch.
Clear specification, lead times and warranty. No vague “from” prices.
Slab, frame and any side/top lights are built to your sizes for neat lines and reliable sealing.
Floors protected, old frame removed carefully, edges sealed and trims finished cleanly. All waste taken away.
If you need anything, you speak to the same friendly team who fitted your door.
Serving Grantham, Stamford, Sleaford, Newark, Bourne, Melton Mowbray and nearby villages.









Yes. Modern doors use thermally broken profiles and high-performance glazing. With correct specification you achieve low U-values and a comfortable hallway.
Very secure. Multi-point locks, robust hinges and quality cylinders come as standard. We can add laminated glass in any side lights.
On many systems, yes. Dual-colour powder coating is common, so you can keep interiors light while the exterior stays bold.
Standard weathered thresholds give the best seal. Low thresholds can work well when exposure and drainage are considered. We’ll explain the trade-offs at survey.
Quality powder coats are highly durable. Routine cleaning and occasional hardware servicing keep everything looking and working as it should.
Like-for-like replacements usually don’t. If you’re changing size or appearance significantly, or in a conservation area, we’ll advise before anything is ordered.
Most single entrance doors are completed in a few hours. Sets with side panels take longer. You’ll get a realistic schedule with your quote.
Yes. We remove the old frame and slab and leave everything tidy.
Trustindex verifies that the original source of the review is Google. I have been using Avanti for 35 years and the service and product quality is amazing!Posted on Google Will mcintoshTrustindex verifies that the original source of the review is Google. Cannot recommend Avanti enough!! Amazing service from start to finish. The whole team were friendly and professional. Great job and have told all my family and friends if they ever need a job doing, to give them a callPosted on Google Natalie BuxtonTrustindex verifies that the original source of the review is Google. We had nine blown windows, called a couple of window companies to try and get the best price and these guys were the only ones who got back in touch with us. We weren't willing to wait around so went with them and I'm glad we did. They came out, took the measurements and ordered the glass. I was advised the glass could take about four weeks which was fine. Less than a week later I got a call asking if there was any chance they could come later today to fit our new windows! They came round and had them all replaced in about an hour!! For the first time since we've moved into our house we have been able to see properly out of our window! Thank you for the professional and prompt service! I would recommend.Posted on Google Lisa KnightTrustindex verifies that the original source of the review is Google. We have this week had our windows installed courtesy of Avanti Windows Grantham. From start to finish we have had excellent service. I knew I was in safe hands when I met Richard who came out originally to measure up and quote, but to be honest everyone we have dealt with from Richard through to the fitting team have been spot on. Very professional. We did get quotes from other well known window suppliers but the out dated sales tactics and tedious process put us off. There was none of that with Avanti…. It was so easy. I would highly recommend them. I’d give 6 stars if I could👍🙏Posted on Google MARK GOODETrustindex verifies that the original source of the review is Google. Amazing firm and very professional. They’ve done a great job In replacing our conservatory roof for a solid one. Punctual everyday and end result it brilliant. Highly recommendPosted on Google George PimTrustindex verifies that the original source of the review is Google. Avanti delivers an outstanding service. I had a new glass roof fitted on my conservatory and the team also refurbished the whole conservatory and made it look like it was new. Fantastic job, exceeded my expectations. I have no hesitation in strongly recommending this company. A big thank you to the whole team at Avanti, a great bunch of guys!Posted on Google Douglas HowcroftTrustindex verifies that the original source of the review is Google. Brilliant company. Quality windows. Staff really friendly and helpful.Posted on Google Chris JonesTrustindex verifies that the original source of the review is Google. Absolutely over the moon with my windows and doors, service and fitting is top notch!! We will be having replacement windows from them in the future!!Posted on Google Toni BlakeyTrustindex verifies that the original source of the review is Google. A patio door leaked because they "forgot to put in drain holes". Ahe door got fitted by "trimming" the opening by wacking it with a lump hammer (even though the builder was on hand with a diamond saw), the windows came scratched and the external paint could be removed with a finger. I saw they hadn't sealed in the window frames and asked why not. Apparently they don't carry sealant!?!? They all got taken out and my builder rebuilt the door opening.Posted on Google Sheila and PeterTrustindex verifies that the original source of the review is Google. Tony and the team were very professional throughout the whole process. The fitters had to install all new windows and doors and have completed to a high standard. They have been very accommodating with my timescales and would highly recommend. Thank you!Posted on Google Evie English