"Avoid like the Plague!!!!"

Awful Experience – Avoid Costello’s at All Costs! Dated Aug this year but it started 3 years ago and still they haven't fixed the problems.

I had the misfortune of hiring Costello’s Windows, and I honestly wish I’d gone anywhere else. From the moment they secured the job, things went downhill fast. The delays were nothing short of infuriating—after the initial promise, it took them five months just to fit the windows. I understand delays happen, but five months after the date promised is absolutely ridiculous, especially when they couldn’t even communicate properly about it.

Once they finally installed the windows, I quickly realised that two windows were wrong as were the two sets of sliding doors. To make matters worse, it took them another few months to fix the issues. And when they eventually showed up, they completely botched the corner window panels—panels that they had originally claimed they could do. They then tried to tell me they “don’t actually do those,” despite me having clear photographic evidence of their shoddy work. Windows are leaking in parts now too!!

To add insult to injury, they were impossible to contact. Calls and emails were routinely ignored or I was told they'd call back, and I had to chase them relentlessly just to get basic answers.

They really couldn’t care less about the customer once they’ve got your money. I’ve never had such a stressful, frustrating experience with a company.

If you value your time, money, and sanity, do NOT hire Costello’s. They’ve proven to be unprofessional, untrustworthy, and downright incompetent. This has been nothing short of a nightmare, and I would strongly advise anyone to stay far, far away. One star is generous if I could give none I would and that's the Gods honest truth.

Dated Aug this year but it started 3 years ago and still they haven't fixed the problems.

"We had a new patio door fitted justify …"

We had a new patio door fitted just before Christmas.Costello’s took my order as urgent, as my old door just died and could no longer be locked. I appreciated this as l could have been waiting much longer for the fitting. Jer fitted the door,made a supper job of it.He was an amazing worker. I would highly recommend Jer,and Costello windows and doors. Eileen.

"A pleasure to deal with from start to…"

A pleasure to deal with from start to finish and a top class job.

Am delighted with the job and would highly recommend Costello Windows.

"They fitted the day they said they…"

They fitted the day they said they would. The quality of the product is really good. I like Jerry the fitter use grey silicone to match the grey in the doors. Breda and Brendan were so easy to deal with

"Everything worked out very well "

The fitter - Jer - did an excellent job - fitting the new door and windows. He was thorough and he obviously enjoys his work. The windows and doors have a quality feel and they look great.

"Quality windows"

Quality windows installed by an experienced and skilled fitter. And they look great too.
Excellent product that represents excellent value.

"New Palladio Door "

Extremely happy with my New
Palladio door it looks amazing
The difference it made to the House appearance is just unbelievable the quality and workmanship is exceptional
The Fitting was done with care and attention to detail by the Fitter who was excellent and very helpful throughout delighted overall
Billy O'Connor

"New Stable door"

I purchased a new front door that was delivered by courier to Belmullet North Mayo because the way up was too far for fitting. I had a great communication with Brenda from the start both in terms of pricing and delivery, very reliable. My own fitter had no problem fitting the door and it looks amazing. Highly recommend Costello windows and doors.

"Look Elsewhere"

Save yourself time, stress & money and look elsewhere.

Awful finish on the inside of the windows which Costellos were made aware of after installation. Never did anything about it.

The window boards were installed in such an awful way. After asking Costellos to redo them, they were still dreadful. For a finish we had to get another windows company to complete this job.

We eventually had the windows assessed in relation to air tightness. The porch, back door and all but 2 windows are leaking air and in need of serious remediation works. Costellos are refusing to carry out such works.

An employee of Costellos drilled into the frame of the porch window. This was done without any prior discussion and again Costellos refused to remedy the issue.

Their contract is solely to protect themselves when issues arise. They happily take your money but don't want to know beyond that.

21st Feb '25:
Even now we are willing to work with Costellos to have our issues resolved and have always shown a willingness to do so but they're only willing to address some of the issues that we have raised which is simply not good enough. They are ignoring the rest.

I've updated this review as I feel so strongly that people should avoid this company. They've been an absolute nightmare to deal with and I regret the day we ever engaged them to supply and install replacement windows.

For your own sake, I strongly urge you to avoid this company and to take your business elsewhere.

I can’t seem to add pictures to this review but if you look at the review I’ve left on Google, you’ll be able to see what I’ve posted there.

"Fantastic Products & Customer Engagement"

I purchased 2 palladio doors with ajoining windows from Costello Windows. My overall experience was very good.

Initial contact - I spoke with Hayden (one of the owners) who was exceptionally pleasant and took the time to dicuss the various options and which would be best. This made me feel at ease and gave me the time to make the correct choice for my house. I had a request to make a side panel in the adjoining window the same height as the panel in the door and he confirmed they would be able to make this.
Overall I am very happy with the quality of the doors/ windows fitted and the service level provided throughout my experience.
Amelia was very pleasant in the after sales service to help arrange an aftersales call out.
John O Sullivan called out for the after sales service. He was very pleasant and fixed a minor issue I had immediately.
Overall I would highly recommend Costello Windows for the products they supply and their support to help the customer in any way possible. They make the experience of getting doors/ windows a very pleasant one.