One of the key things with the budgeting is trying to get it as accurate as possible. There are always going to be unknowns, so there is always going to be the need for some contingency.  However, if you can reduce the unknowns to the minimum, this is going to reduce the likelihood of any surprises.

So looking at the current estimates, there are a number of big unknowns…..

Problem
Issue
Mitigation
State of the existing roof
Will it need to be replaced? What condition are the roof trusses in?
We have looked in the loft (of No. 8 only) and the roof looks to be in fairly reasonable condition.  The roof trusses are nothing special (very plain), but the perlings look good.  Not sure that there is a lot of merit in opening up the roof space.  The cost of refurbing the existing roof is estimated at around £14,000, so not a huge sum relatively.
Foundations of the walls in the barn
Are there any foundations in the barn or has it been built directly onto the earth below.
We have no idea on this until work states.  In the budget, we have assumed the worst and included the costs of completely rebuilding the walls (to include foundations).
Condition of the septic tank
This was installed in the 1970’s.  It is an 800 gallon tank, so is plenty big enough, but what state is it in?  Also the design is fairly dated and the water simply soaks away into the bottom field.
The top seems pretty rotten, but it is clearly still operational.  We need to get a specialist in to provide some advice.  If the septic tank could last a couple of more years, it could be replaced at a later date.  Specialist help needed.
Floors (particularly upstairs in No. 8)
These are fairly “springy” in places and certainly do undulate.
Pulling back the carpets revealed some very poorly laid tongue and groove chipboard.  The underlying joists appear to be ok.  New floors required and included in estimates.
Refurb of the office space
Originally, the office space was going to be above the double garage that has now been removed from the plans due to costs.  The current plan is to build some office space into the existing coal hole.
The space is odd and quirky.  The walls are singled skinned (but original) and the floor is made up of flagstones.  There is some modern block work inside.  Some of this appears to be helping structurally.  Mark (the architect) to provide a quote.