Easy cleaning. Safe ventilation. Modern performance.
Tilt & turn windows open in two ways: tilt from the top for secure ventilation, or turn inwards for a wide, easy-clean opening. They are ideal for upstairs rooms, tight spaces and homes that want neat lines with practical day-to-day use.
We supply and fit tilt & turn windows across Grantham, Stamford, Sleaford, Newark, Bourne, Melton Mowbray and nearby villages. Every frame is made to measure for your home.
Two opening modes
Tilt for safe background air flow or turn inwards for full access and cleaning from inside.
Great for upper floors
Clean upstairs glass without leaning out or ladders.
Secure ventilation
Night-safe tilt position helps air the room while keeping the opening restricted.
Strong energy performance
Modern frames and glazing help keep rooms comfortable and bills sensible.
Modern look
Clean sightlines suit contemporary refurbishments and extensions.
• Single large sash for a clear view • Paired sashes for wider openings • Fixed lights coupled to tilt & turn sashes for feature windows
• Popular smooth finishes: white, cream, anthracite, black • Timber-look foils for character properties • Dual colour options for different interior and exterior tones
• High-performance double glazing as standard • Acoustic or laminated glass for noise and security • Privacy and decorative options for bathrooms and side elevations • Solar control where the room runs hot
• Discreet handles in modern finishes • Child-safe restrictors available • Trickle vents where required by regulations We will help you balance clear views with safe ventilation during your survey.
Low-e coatings, argon-filled units and warm-edge spacers help achieve low U-values. You feel the difference most in bedrooms and living spaces that used to lose heat quickly.
If you are on a busier street, thicker or laminated glass with tight seals reduces outside noise.
Multi-point locking and robust hinges are standard. Laminated glass can be specified at ground floor or in vulnerable positions.
Better glass edge tech and compression seals reduce the cold band that causes internal condensation.
Not sure which suits each room We will show you samples and layouts on survey so you can choose with confidence.
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 your reveals and talk through sizes, colours, glazing and hardware. It is a conversation, not a pitch.
Clear specification, timelines and warranty. No vague “from” prices.
Built to your sizes for neat lines and reliable seals.
Floors protected, old frames removed, edges sealed and trims finished neatly. All waste taken away.
If you need us, you speak to the same friendly team who fitted your windows.
Serving Grantham, Stamford, Sleaford, Newark, Bourne, Melton Mowbray and nearby villages.




Yes. The tilt position allows background ventilation without a wide opening. We can add restrictors for extra safety.
Yes. The inward turn function lets you reach both sides easily on upper floors.
Modern frames, A-rated glazing and tight seals help achieve low U-values and reduce draughts compared to older windows.
Like-for-like replacements usually do not. If appearance changes or you are in a conservation area, we will advise before anything is ordered.
With multi-point locking, robust hinges and optional laminated glass, tilt & turn windows are very secure.
They can be wider and taller than many casements because they are supported on strong hardware. We will confirm maximum sizes for your chosen system.
A typical three-bed semi is often completed in one to two days depending on access and the number of openings. You will get a realistic schedule with your quote.
Yes. We take away old frames, sealed units and packaging and leave rooms 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