If it means "right this minute" then BS will probably want to withold a proportion of mortgage until it''s done. If not it probably means "within the life of the mortgage". Best bet would be to get a free quote from a couple of builders. May also be used as a bargaining point when agreeing a price.
I''m not a builder, so you''re welcome to dismiss the following;)
I read that as meaning that you need some stones replacing.
I''d have thought that was the kind of project that ought to be underway before next winter.
450mm is 18", so I wouldn''t think it''ld be a quick/cheap/DIY project.
Maybe it''s a bit alarmist, to cover themselves if it falls down.
Without seeing what we''re talking about, I''d suggest thinking about having a chat with a "proper" builder.
A Homebuyer''s survey is one up from a mortgage valuation but not as detailed as what used to be a full structural, nowadays called a Building Survey.
As a homebuyer''s survey is commissioned by you rather than the lender (you don''t mention if you are having a mortgage and if you are, you will also have had a mortgage valuation carried out). The mortgage valuation purely confirms to the lender that the property is satisfactory for them to lend on and therefore if you are having a mortgage, you will need to look at the mortgage offer in conjuction with the mortgage valuation to see if there are any special conditions attached to the offer. This is where you will see if there are any time limits or must do''s attached to the offer.
If you are not having a mortgage and have commissioned a homebuyer''s for your own benefit, you will find that as it is a more detailed survey, the surveyor will be doing a measure of a*se covering and often if read literally, it will seem like the house is about to fall down!!
I would suggest regardless of which scenario described above is pertenant to you, that you then arranage through the agents (if you are buying through agents) to bring two or three reputable builders along to the property to give you a quote on the necessary works and for them to give an opinion on what is required to be done now and what can wait - then if you think the cost for the works deems you renegotiating the price you have agreed, go ahead and do so.
One must do however, is as you have mentioned the property is listed, depending upon what grade of listing it has, you may have to get permission through the council before having ANY works done at all. Again, depending upon the grading, you may also have to have permission for internal works, change of windows, possibly even change of external colour etc etc.
Buying a listed building can have some drawbacks as mentioned above, however on a positive note, you can also qualify for grants for some works.
Whatever you do, check what you are allowed to do or not allowed to do before you undertake any works otherwise a particularly pernickity local authority could get heavy with you. They can also get heavy with you if you do not undertake works that they would consider necessary.
Very exciting time for you though, the property sounds lovely
I am not a builder but I am fairly sure in saying its not going to heal itself over time, it will get worse unless you do something. Epitome gives some good advice, particularly as the solid walls suggest that the property is quite old (houses built after the 1930''s were usually built with cavity walls, just like the Romans). If the stone work is eroding then perhaps it is a sandstone/limestone rather than something more resistant, so you would almost certainly have to repair with ''local'' stone. Also worth noting if it is of solid wall construction the walls are going to be structural so not really something for a first-time DIYer to tackle.
''The stonework is worn and eroded, appreciable remedial works can be anticipated if further deterioration is to be avoided"
Everything deteriorates, accelerated deterioration can be avoided by routine maintenance. So what if the stonework is eroded. Look at any historic listed building/monument, they are all worn/eroded in some way.
My first guess would be that your gutters and any dripstones may need repair, after that some repointing may be required. This is usual stuff and technically not an issue. I would need to have sight of the report to comment further and to put it into context.
I would point out that any remedial/maintenance works will need to be cleared with the conservation officer of the local authority and possibly English Heritage, depending on the degree of listing, the extent of the works and any grants previously having been received.
Like Lostboy67 I don''t recommend DIY-ing listed buildings unless of course you are a traditional craftsman/woman.