What would be the best standard form for a groundworks contract for about £400k of trenching across land
The idea is that with the NEC family of contracts there is a contract for any type of contract. This one would be a straight choice between the Engineering and Construction Contract (ECC) or the Engineering and Construction Short Contract (ECSC). The short contract is intended for more low risk straight forward work with not too much change envisaged. So although £400k is relatively low value in the scheme of things, it could still be quite complex with lots of potential risk and change likely to occur which will significantly increase the value in which case I would choose the ECC.
The short contract is easier to manage and less administrative and therefore if you think your groundwork’s fits the bill then it is a good contract to use. Otherwise if you are in two minds I would always use the ECC contract which is more detailed but then protects you administratively, You then also have to choose whether you want primary option A/B/C/D/E/F (the short contract has no options). It is likely that for straight forward well defined works you would be choosing a lump sum type of contract which would either be options A or B (and you can search other existing answered questions for more detail on those).