Is a 10% asking price offer reasonable here?

[lacrema]

We've recently seen a house in the area we are looking to buy. It's been on the market for 3.5 months. When it went on, good houses were still selling very quickly. Things have slowed a bit but only the over priced/ not appealing houses aren't moving as there is a massive lack of supply compared to normal times.
We really like the house and it suits our needs but it does have a couple of quite significant factors that are probably putting would be buyers off, one being that it's at the higher end of the market for this town but isn't detached which many people find important.
Would a 10% below asking price offer be cheeky/ offensive in these circumstances?

10% below asking price is fine to offer, especially if that’s in line with the market

Many thanks @BasementIdeas. Hard to tell what's in line with the market as nothing else comparable.

I don’t see how anyone could be offended by an offer 10% below. We ended up accepting an offer below this but it is very dependent on area as to whether the vendor can realistically hope to achieve close to the asking price or not

You offer what you genuinely think it is worth, they can accept, negotiate or refuse.

10% unreasonable
90% totally reasonable ;) . We did that on ours. Whether it gets accepted will depend on area and demand.