EPC Rating E (2013 certificate) on house I'm considering buying – how concerning is this?

Hi all,

I'm currently considering buying a house built in the early 1990s in the UK, and noticed that the EPC rating is E. The certificate was issued in 2013 and expired in 2023, so it's quite old, and I'm unsure how representative it still is.

From the EPC details, the points that concern me are:

• Walls: Cavity wall, but no insulation assumed (Poor)
• Roof: One entry shows 100mm loft insulation (Average), but another says no insulation assumed (Very poor), which seems contradictory
• Lighting: No low-energy lighting (Very poor)
• Floor: Solid floor with no insulation assumed
• Primary energy use: 316 kWh/m² per year

My understanding is that the lighting issue is probably easy to fix by switching to LED bulbs, so I'm not too worried about that.

My main concern is the roof section, because the EPC seems to show two different assumptions — one saying 100mm loft insulation and another saying no insulation is assumed, which seems contradictory.

A few questions for those with experience:

1. How seriously should I take a 2013 EPC? Could the rating realistically be better if reassessed today?
2. For a 1990s house, is it normal for the EPC to assume cavity wall insulation is missing, or is that unusual?
3. The roof section looks contradictory (100mm insulation vs no insulation assumed). Is this common in older EPCs?
4. Roughly how expensive would it be to move a house like this from E → C or D?
5. Is this a normal EPC profile for early-90s houses, or does this raise any red flags?
6. Should I just wait for a surveyor to properly assess insulation and roof conditions, or is this something worth investigating before making an offer?

For context, I'm a first-time buyer trying to understand whether this is a normal upgrade situation or a potential money pit.

Any thoughts or experiences would be really appreciated.