Secure, stylish and made to measure.
A good front door should feel solid, lock properly and look the part every day. Our composite doors combine a tough, insulated core with durable skins and quality hardware for a warm hallway, quiet nights and proper security.
We survey, supply and fit across Grantham, Stamford, Sleaford, Newark, Bourne, Melton Mowbray and nearby villages.
Insulated core, quality seals and high performance glazing reduce draughts.
Multi-point locking, robust hinges and secure cylinders as standard. Laminated glass available for side panels.
Weather-resistant skins that do not peel or flake. Wipe clean maintenance.
Classic, cottage and contemporary styles with a wide choice of colours, glass and hardware.
Thermal performance
Insulated cores, tight compression seals and high performance glazing help keep heat in. You notice it most around the hall and stairs where older doors often leak air.
Security
Multi-point locking engages around the frame. Anti-bump cylinders and reinforced hinge points resist forced entry. Laminated glass is available for added protection.
Noise reduction
Better seals and laminated glass options help cut traffic noise on busier streets.
Longevity
Durable outer skins and serviceable hardware. No yearly sanding or repainting. A quick clean keeps it looking new.
We’ll talk you through choices during survey, but here’s what’s typical:
If you’re trying to keep the original look of the house as close as possible, bring photos of how it used to look (even from old estate agent listings). We can work from that.
We know people worry about two things: mess, and being sold to. Here’s how we handle both.
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 styles, colours, glass and hardware. It is a conversation, not a pitch.
Clear specification with lead times and warranty. No vague “from” pricing.
Door slab, frame and any side panels are built to your sizes for neat lines and reliable sealing.
Floors protected, old frame and slab removed, 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.














Very secure. Multi-point locking, quality cylinders and robust hinges come as standard. Laminated glass is available for side panels and larger glazed sections.
Yes. The insulated core and proper seals reduce draughts and heat loss compared to older timber or first-generation uPVC doors.
A composite door has a dense, insulated core and a stronger skin. It feels more solid, holds heat better and often looks closer to timber.
In most cases, yes. There is a wide palette of colours and a choice of handles, letterplates and knockers. We bring samples to your survey.
When specified correctly, yes. We will explain the pros and cons so you can balance access and weather performance.
Like-for-like replacements usually do not. If you are changing size or adding new glazing, we will advise before anything is ordered.
A single front door is often completed in a few hours. If we are also replacing side panels or doing remedial work, it can take longer. You will get a realistic schedule with your quote.
Yes. We take away old frames, panels and packaging 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