Delayed Access JCT SBC/Q 2016

If a Contractor has access delayed by the Employer, then this is both a Relevant Matter and a Relevant Event. However, if the delayed access causes the contract completion to move from say summer time to winter time, then this would likely incur additional costs later in the project due to having to work through winter rather then summer, i.e., a higher frequency of Adverse Weather Events, flooding, less daylight etc…As Adverse Weather is not a Relevant Matter, then how would a Contractor go about claiming for these prospective additional costs under the JCT contract within the delayed access claim?

Under an NEC contract where quotations are forecasted I believe the solution is fairly straightforward, as the CE mechanism would allow you to forecast increased working durations and apply a risk percentage to cover the increased frequency of weather events.

Under a JCT Contract the only solution I could see would be under clause 4.21.3, to keep submitting quotations at monthly intervals until the actual costs could be established. If you had to do this for 6-months where there are no increased costs in the interim, it seems a little illogical.

I’m sure this issue must rear it’s head fairly regularly for Contractor’s and I was wondering if anyone has dealt with this issue before, or could present a better solution than the one I have outlined above?
I would be very grateful for any input.